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By:. Introduction. What is a control valve. The available configurations and sizes. The construction of a basic control valve. The different component.

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Presentation on theme: "By:. Introduction. What is a control valve. The available configurations and sizes. The construction of a basic control valve. The different component."— Presentation transcript:

1 By:

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3 Introduction. What is a control valve. The available configurations and sizes. The construction of a basic control valve. The different component specifications. The operating principle. Understanding the two types of control systems. Factors to consider when selecting a control valve.

4 Pilot Valves.Valve accessories - Questions relating to hydraulic relays. Understanding electric solenoid valves. Other devices and fittings. A few commonly used valve examples -Open / Close Valves. Pressure Regulating Valves.

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6 A control valve is a semi - automatic directional device which controls flow and or pressure within a water supply network. Control valves are generally set to the required operating parameters on installation and thereafter require no further operator intervention.

7 Threaded connections - 40mm, 50mm, 65mm, 80/65/80mm & 80mm Flanged connections - 80mm, 100mm, 150mm & 200/150mm Inline Valves Threaded connections - 50mm, 65mm, 80/65/80mm & 80mm Angle Valves

8 Gator control valves are constructed from 5 main components. These are: The Bonnet The Spring The Spring Retainer Disk The Diaphragm The Body

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10 The Bonnet. Materials - Manufactured from grade 14 cast iron. Coatings – Fusion bonded epoxy powder coated. External Coating – UV stabilized polyester coated. Internal Coating – Chemically stabilized epoxy coating. Other coating options are available on request. Control System Ports - Number of control ports - 2 Thread type - BSP or NPT. Port sizes - On the 50, 65, 80/65/80 &150 valves, both ports are 1/4" On the 80 & 100 valves the center top port is 1/2" and the angled side port is 1/4" Markings - Directional indication arrow, valve name & valve size in metric format. Optional Devices - A mechanical throttle can be fitted to the valves bonnet allowing the valves pressure to be adjusted. The mechanical throttle allows for pressure control on the valve in systems where the upstream pressure before the valve is always the same. A valve fitted with a mechanical throttle is not a modulating valve. A valve fitted with mechanical throttle

11 The Spring Materials - Manufactured from Stainless Steel. Finish - Ground on bottom end to accommodate spring retainer disk. The Spring Retainer Disk Materials - Manufactured from Glass Reinforced Nylon. Finish - Fitted with locator hole to locate the diaphragm. The Bolts, Nuts & Washers Materials - Manufactured from 304 grade stainless steel. Thread Specifications - Metric standards. General - Bolts are of the set screw type. Nuts are of the Nylok type and washers are plain flat washers.

12 The Diaphragm Materials - Manufactured from SMR 20 Natural Rubber and center reinforced with RFL treated Woven Nylon Cloth. Other materials, such as, EPDM, Nitrile and Neoprene are available on request. Note !!! - Gator valve diaphragms used in clean, dirty, untreated or treated effluent water are guaranteed for one year. Flow Convergence Ribs – DN80, DN100 & DN150 diaphragms are moulded with Flow Convergence Ribs to allow smoother operation of the valve at lower flows. Regulation is also possible at lower than normal flows without vibration occuring in the valve.

13 The Body Materials - Manufactured from grade 14 cast iron. Control System Ports - Number of control ports - 2 1 upstream and 1 downstream Thread type - BSP or NPT. Port sizes - All ports are 1/4" End Connections - Flanged options are: BS10 Table D/E/F, ISO PN10/16/25, ANSI 125/150/ 250/300 & JIS 10/20. Threaded options are: BSP or NPT. Markings - Valve name and valve size (in metric format). General - The Gator valve body is symmetrical and can therefore be used in either direction. This however does not apply once the control network has been plumbed onto the valve. The valve should be installed in accordance with the directional arrow on the bonnet. Coatings – Fusion bonded epoxy powder coated. External Coating – UV stabilized polyester coated. Internal Coating – Chemically stabilized epoxy coating. Other coating options are available on request.

14 Single Chamber Outlet Inlet Weir Gator valves are simple single chamber inline or angle control valves which operate using the available pipeline pressure or an external pressure supply of air or water, provided this pressure is equal to or greater than the pressure of the pipeline, in which the control valve is installed.

15 To open the valve. To open the valve, the water or air trapped within the upper chamber is released into atmosphere or into the downstream of the valve, into the pipeline. The diaphragm is forced upwards by the pressure within the pipeline allowing the valve to open. Inlet Outlet Upper Chamber

16 To close the valve. Inlet Outlet Upper Chamber To close the valve, water or air pressure is induced into the upper chamber forcing the diaphragm to close against the weir within the valve and thereby stopping the flow of the liquid within the pipeline. Weir

17 The hydraulic closing action. b) The spring aids the valve to close specifically when friction loss is at a minimum. When friction loss across the valve is sufficient, the spring plays little or no role. Although the surface areas above and beneath the diaphragm are equal, the valve will close when water (which is at equal pressure within the pipeline upstream of the valve) is induced into the upper chamber due to the following reasons: a) Under closing operation, the hydraulic energy above the diaphragm is greater than beneath the diaphragm due to the friction loss generated across the valve. For example if the upstream operating pressure within the pipeline is 5 Bar and the valve has a friction loss of 0.3 Bar, the pressure beneath the diaphragm would vary between 5 (upstream) and 4.7 Bar (downstream) while the pressure on the full upper surface of the diaphragm is 5 Bar. The more the valve closes the higher the pressure differential between the top of the diaphragm and below the diaphragm, thus causing the valve to close securely. 5 Bar4.6 Bar5 Bar3 Bar5 Bar0 Bar 543 4.9 4.8 4.7 Fully Open ValveClosing ValveFully Closed Valve 00 5 55 5 55

18 The regulating mode. Inlet Outlet Upper Chamber By incorporating other control mechanisms, the valve can be adapted to regulate flow without being fully closed or fully open. The valves diaphragm is the only moving part and is assisted to close under all pressures with the aid of a spring.

19 The three way system. There are two control systems utilized by single chamber valves. These are, the three way control and system and the two way control system. Definition - A selector valve, activated manually, and/or electrically, by upstream media pressure or by an external media pressure. The valve generally has three positions of operation. Position 1 - When pressure is induced into the control chamber the valve will close. The Closed Valve 1 Selector Valve The Open Valve 2 Selector Valve The Regulating Valve 3 Selector Valve Position 2 - When pressure is relieved from the valve chamber into atmosphere, the valve will open. Position 3 - When the flow path from the selector valve to the control chamber is closed, the position of the diaphragm is set. This situation is not applicable to OPEN/CLOSE control valves but is required for modulating valves.

20 Use a 3 Way Control System When : OPEN - CLOSE valves are required. Low pressure differential is required. The controlled media is a very dirty or abrasive liquid. The control media is different from the controlled media (within the pipeline) e.g. Pneumatic control of water network. Do NOT use a 3 Way Control System When : Extreme fluctuations in network operating conditions are anticipated. No Flow (shut off) situations are expected. The three way system. The Closed Valve 1 Selector Valve The Open Valve 2 Selector Valve The Regulating Valve 3 Selector Valve

21 Definition - A control configuration of two flow restricting devices working together to control the valve. Flow restrictor "a" is a fixed passage restrictor fitted to the upstream of the control network (Normally a needle valve is used for this task). Flow restrictor "b" is either an OPEN - CLOSE device or modulating pilot valve which is fitted to the downstream control network of the valve. When this device is fully open the passage within the device should be larger than the passage of restrictor "a" The control valves operation is effected by the downstream restrictor device "b" in the following ways: Position 1 - When device "b" is fully closed, the valve will close, due to the fact that the control media cannot vent into the downstream. In this position, the surface area above the diaphragm is ± 2 x greater than the surface area beneath the diaphragm, thus causing the valve to close. The Closed Valve 1 a b The Open Valve 2 ab The Regulating Valve 3 ab The two way system. Position 2 - When device "b" is fully open, the valve will open to a point where the pressure in the control chamber is equal to the pressure in the downstream of the control valve. As the volume of control media which can pass through restrictor "a" is less than what can pass through restrictor "b", the pressure above the diaphragm is less than the pressure beneath the diaphragm, causing the valve to open. Position 3 - When the flow passage of device "b" is modulated, the relationship between device "a" and "b" will cause the valve to respond to this modulation. The valve will position itself to the pre-set pressure of the pilot valve "b" On pressure change in the system, device "b" will alter it's passage opening causing the control valve to respond as well.

22 The Closed Valve 1 a b The Open Valve 2 ab The Regulating Valve 3 ab The two way system. Use a 2 Way Control System When : Sensitive regulation at low pressure is required. A pressure differential is required at all operating conditions. Little pressure reduction is required. Simplicity of control and setting of the valve and system are essential. NO flow (shut off) regulation is required. Do NOT use a 2 Way Control System When : When full opening of the control valve is required for absolute minimum pressure loss under certain operating conditions. When the control media is not the same as the controlled media in the pipeline. When the controlled media is very dirty or abrasive. Note !!! The setting of the needle valve "a" can have an important effect on the pressure loss across the control valve. The smaller the passage in this device, the less the friction loss across the valve, however, the slower the response time of the control valve. Slow response time can lead to over pressure within the control system.

23 Pressures. Temperatures. Media Velocities Pressure Loss. Cavitation. Pressure Reduction. Open Discharge Systems. Three way or two way operation ?

24 Pressures. The Minimum Operating Pressure. The Maximum Operating Pressure. The minimum pressure required to open all Gator valves is 7 meters. Check to ensure that the system upstream pressure is not below 7 meters as this can cause the valve not to open or to only partially open. A partially open valve will cause higher than normal friction loss which could result in poor and inaccurate valve performance. All Gator valves are rated to operate at a maximum shut off pressure of 160 meters (16 Bar). Although tests conducted on Gator valve diaphragms have confirmed that all the diaphragms can handle up to 250 meters (25 Bar) of pressure, valves should not be designed for operating conditions above 16 Bar. 123045678910111213141617181920 No OperationRecommendedAcceptedNot Recommended 123045678910111213141617181920 Operating Pressure in Bar Minimum Operating Pressure 0.7 Bar Maximum Operating Pressure 16 Bar

25 Operating Temperatures. The Maximum Operating Temperature. The maximum operating temperature for Gator valves fitted with standard SMR 20 natural rubber diaphragms is 70° Celsius. Consult with your supplier for valves which are to be used at higher operating temperatures. Max 70° C

26 Media The media with which a Gator valve is to be controlled. This can be defined as the media within the pipeline which is controlled by a Gator valve. Gator valves are suitable for controlling slurries, untreated sewage water, water with a high sand content as well as most normal media types which are generally controlled by such valves. This is possible due to the design of the valve which has no shafts, bearings, seals or discs. This can be defined as the media which is used to control the valve. This media is generally the same as that which is in the pipeline into which the control valve is installed. It is however possible to use an external media. This can be air or clean water and should be used if the media within the pipeline is dirty or abrasive. The media to be controlled by a Gator valve.

27 Velocities. Gator control valves may be used at very high velocities due to the weir shape of the valves body, which is almost turbulence free. The valve may be operated in the fully open position at 7-8 m/sec. velocity without noise, shuddering or cavitational damage.

28 Pressure Loss. Due the valves construction, the water passes through the valve with minimal direction change, therefore keeping head loss to a minimum. In certain applications (such as pressure reducing operations), it t is often advantages to select a valve that has a slightly higher head loss in order to obtain a more positive and direct response from the control valve. Note !!! Head loss in valves fitted with two way control systems is higher than valves fitted with 3 way control systems.

29 Cavitation. This is the term used for the formation and subsequent collapse of vapour bubbles in the regions of low pressure within a flowing liquid. Cavitation is caused by the liquid in the system passing through the throttling section of the valve, it's velocity increases and it's pressure decreases below the liquid's vapour pressure, and vapour bubbles are formed. Throttling Section Vapour Bubbles Damage Zone Downstream of the valves throttling section, flow suddenly expands, it's velocity decreases and static pressure recovers. When recovered pressure increases above vapour pressure, it causes a violent collapse of the vapour bubbles which result in intense heat and shock waves which will eventually destroy any material they contact. If the downstream pressure is less than vapour pressure, (e.g. atmosphere) bubbles will remain in vapour state and cavitation is prevented. Cavitation in Gator valves can occur when the pressure reduction ratio between the upstream and the downstream exceeds a 3:1 ratio. Cavitation damage can be identified by : Noise and vibration in the valve and ajoining pipework, an unexplained rise in headloss and erosion of the valve and ajoining pipework.

30 Pressure Reduction. Where the pressure reduction ratio across the valve exceeds 3:1 or where cavitation damage can be caused, it is recommended to implement one of the following solutions. Solution 1 - Install two valves in series, setting each valve to create a pressure reduction within the 3:1 reduction ratio. Solution 2 - Install an orifice plate in series with a reduction valve on the upstream of the pipeline. This solution is limited to systems where the flow rate will not vary by more than 10% of the average flow. Solution 1 Solution 2 100 mts 50 mts 20 mts Reduction Ration 2 : 1Reduction Ration 2.5 : 1 100 mts 50 mts 20 mts Reduction Ration 2.5 : 1 Reduction Ration 2 : 1 Orifice Plate

31 30 mts 25 mts Head loss over valve = 5mts 25 mts Reservoir 2 mts Float Pilot Valve Orifice Plate Head loss over orifice plate = 23mts Open Discharge Systems. When a valve is situated very near the end of a pipeline and the pipeline discharges into atmosphere, cavitation can occur. This is typical in installations involving level control valves and relief valves. By installing an orifice plate directly after the valve, potential cavitation and damage can be prevented from occurring. This is not applicable when the valve discharges directly into atmosphere.

32 Three way or two way operation ? Use a 3 Way Control System When : OPEN - CLOSE valves are required. Low pressure differential is required. The controlled media is a very dirty or abrasive liquid. The control media is different from the controlled media (within the pipeline) e.g. Pneumatic control of water network. Do NOT use a 3 Way Control System When : Extreme fluctuations in network operating conditions are anticipated. No Flow (shut off) situations are expected. The three way system. The Closed Valve 1 Selector Valve The Open Valve 2 Selector Valve The Regulating Valve 3 Selector Valve

33 Three way or two way operation ? The Closed Valve 1 a b The Open Valve 2 ab The Regulating Valve 3 ab The two way system. Use a 2 Way Control System When : Sensitive regulation at low pressure is required. A pressure differential is required at all operating conditions. Little pressure reduction is required. Simplicity of control and setting of the valve and system are essential. NO flow (shut off) regulation is required. Do NOT use a 2 Way Control System When : When full opening of the control valve is required for absolute minimum pressure loss under certain operating conditions. When the control media is not the same as the controlled media in the pipeline. When the controlled media is very dirty or abrasive.

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35 Pilot Valves.Valve accessories - Questions relating to hydraulic relays. Understanding electric solenoid valves. Other devices and fittings. A few commonly used valve examples -Open / Close Valves. Pressure Regulating Valves.

36 Brass Pilot Valve Range 3WUI Universal 3 Way Pressure Reducing & Sustaining 16 Bar 1 to 12 Bar 1/4" Fem. BSP or NPT 40 to 200 mm 2WPR Universal 2 Way Pressure Reducing 16 Bar 1 to 12 Bar 1/4" Fem. BSP or NPT 40 to 200 mm 68-500 Relief 2 Way Quick Relief with Built in Needle Valve 16 Bar 1 to 12 Bar 1/4" Fem. BSP or NPT 40 to 200 mm Model Pilot Type Control System Type Function Maximum Pressure Rating Pressure Setting Parameters Port Connection Sizes Port Threads Suitable for Valve Sizes

37 Plastic Pilot Valve Range Model Pilot Type Control System Type Function Maximum Pressure Rating Pressure Setting Parameters Port Connection Sizes Port Threads Suitable for Valve Sizes XR 100 Pressure Reducing 3 Way Pressure Reducing with Built in Manual Override 10 Bar 1 to 6.5 Bar 1/8 Fem. BSP 40 to 200 mm Pressure Reducing, Sustaining & Relief XR 101 Universal 3 Way 10 Bar 1 to 6.5 Bar 1/8 Fem. BSP 40 to 200 mm Pressure Reducing with Built in Manual Override SG 2000 Pressure Reducing 2 Way 10 Bar 1 to 7 Bar 1/8 Fem. BSP 40 to 200 mm

38 What is a hydraulic relay ? Provide a few examples of hydraulic relays commonly used in the irrigation industry ? How does a hydraulic relay work ? Provide a few examples of where a relay would be used ?

39 A hydraulic relay is a hydraulic device which actuates change within a hydraulic network on receipt of an hydraulic signal. What is a hydraulic relay ?

40 The Shastomit - A 3 way normally open relay manufactured by Arad Dalia of Israel The Shastomon - A 3 way normally closed relay also manufactured by Arad Dalia of Israel. The Matmar - A 3 way universal relay manufactured by Bermad of Israel. A few examples of hydraulic relays commonly used in the irrigation industry ? The G2000 - A 3 way universal relay manufactured by Mad Takin of Israel.

41 How does a hydraulic relay work ? The deactivated mode The activated mode Remote Operation 42 3 1 4 OpenClosed Auto OpenClosed Auto Remote Operation OpenClosed Auto OpenClosed 42 3 1 4

42 Provide a few examples of where a relay would be used ? Example 1 - Controlling a valve remotely using the local pressure at the valve.

43 Provide a few examples of where a relay would be used ? Example 1 - Controlling a valve using the local pressure at the valve. Description - The control panel is often distant from the valves which are controlled using hydraulic tube as the interface between the control panel and the valve. Problems experienced - Generally slower and sluggish reaction time when opening and closing the valve. Hydraulic command tube to valve laid over distances of 50 meters or more Irrigation control valve Location of irrigation control panel and solenoids. WITHOUT A RELAY

44 Provide a few examples of where a relay would be used ? Example 1 - Controlling a valve using the local pressure at the valve. Description - The control panel is often distant from the valves which are controlled using hydraulic tube as the interface between the control panel and the valve. Benefits - Quicker valve reaction time when opening and closing the valve. Location of irrigation control panel and solenoids. Hydraulic command tube to valve laid over distances of 50 meters or more Irrigation control valve V. P. C. Com. Hydraulic Relay WITH A RELAY

45 Provide a few examples of where a relay would be used ? Example 2 - Overcoming elevation problems within a hydraulic control system. Example 1 - Controlling a valve remotely using the local pressure at the valve.

46 Provide a few examples of where a relay would be used ? Example 2 - Overcoming elevation problems with in a hydraulic control system. Description - The control panel is often positioned higher than the valves which are controlled using hydraulic tube as the interface between the control panel and the valve. Problems experienced - It is unlikely that the valve will open or if the valve does open, it will not open fully. Irrigation control valve Elevation difference between the control solenoid (valve vent) position and the valve exceeds 1 meter Location of irrigation control panel and solenoids. WITHOUT A RELAY

47 Provide a few examples of where a relay would be used ? Example 2 - Overcoming elevation problems with in a hydraulic control system. Description - The control panel is often positioned higher than the valves which are controlled using hydraulic tube as the interface between the control panel and the valve. Location of irrigation control panel and solenoids. Irrigation control valve Elevation difference between the control solenoid (valve vent) position and the valve exceeds 1 meter V. P. C. Com. Benefits - Positive and quick valve opening and closing. Note !!! A suitable spring should be selected for each relay, to accommodate the elevation difference between each valve and the control panel. WITH A RELAY

48 Provide a few examples of where a relay would be used ? Example 2 - Overcoming elevation problems within a hydraulic control system. Example 3 - Inverting a back flush valves operation. Example 1 - Controlling a valve remotely using the local pressure at the valve.

49 Provide a few examples of where a relay would be used ? Example 3 - Inverting a back flush valves operation. Description - Most irrigation filters are fitted with automatic back flush valves. If two separate valves are used for to achieve the back flush operation a relay is required to swap the action of the two valves simultaneously. Back flush valve during normal operation Normally Open Valve (main valve) Normally Closed Valve (flush valve) Hydraulic Relay During normal operation this valve vents to open During normal operation this valve is closed

50 Provide a few examples of where a relay would be used ? Example 3 - Inverting a back flush valves operation. Description - Most irrigation filters are fitted with automatic back flush valves. If two separate valves are used for to achieve the back flush operation a relay is required to swap the action of the two valves simultaneously. Back flush valve during flush mode Normally Open Valve (main valve) Normally Closed Valve (flush valve) Hydraulic Relay During flush mode this valve closes. During flush mode this valve vents to open.

51 What is a solenoid valve ? How a solenoid valve works. The different modes of powering solenoid valves. The difference between a 2 way a 3 way solenoid valve. The difference between normally open and normally closed solenoid valves.

52 What is a solenoid valve ? It can therefore be said that a Solenoid Valve is thus an electrically operated device for controlling the passage of liquid or gas or the likes through pipe. A Valve can be defined as an automatic or other device for controlling the passage of liquid or gas or the like through pipe, etc. A Solenoid can be defined as a cylindrical coil of wire which when an electric current is passed through, it behaves as a bar magnet.

53 How a solenoid valve works. To better understand the operation of a solenoid valve, it would be beneficial to acquaint yourself with the components within the solenoid operator. The solenoid bobbin is wound with copper wire to create the solenoid coil. The solenoid housing is equipped with the solenoid coil. The plunger housing is equipped with the plunger. The plunger shaft. The plunger is fitted with the plunger seal. The plunger seal. The solenoid housing is equipped with the plunger housing and filled with potting resin. The complete solenoid operator The Operators Components

54 How a solenoid valve works. How the solenoid operator functions. The Operator Coil The Plunger De - Energized mode Energized mode In the de-energized mode, the plunger moves freely in the hollow core of the solenoid operator. Generally, the plunger is fitted with a spring in order to force the plunger in a downward motion. In the energized mode, the operator coil creates a magnetic field, which draws the plunger into the hollow core of the solenoid operator. The plunger is held in this position, either by a continual electrical supply to the solenoid operator coil (in the case of most standard ac or dc solenoids) or by means of a magnet (as used in a dc latch solenoid).

55 How a solenoid valve works. The solenoid valves components. The solenoid operator The solenoid base Example of a typical 3 way solenoid valve and base. A complete solenoid valve including operator and base. It should be noted that not all solenoid valves are fitted with bases, as in this case. Many plastic injection moulded electrical irrigation valves use 2 way solenoid operators mounted directly onto the valves lid.

56 How a solenoid valve works. Cross section of a 3 way solenoid valve. Port 1.Port 2. Port 3. The solenoid operator is fitted to a valve base which is equipped with ports. The plunger within the solenoid body is fitted with rubber seals on either end. De-activated Port 2.Port 1. Port 3. When the solenoid is de-activated, the plunger is forced down by the presence of a spring. In so doing, port 1 is sealed and ports 2 and 3 are connected. Port 2.Port 1. Port 3. Activated When the solenoid is activated, the plunger is lifted by the magnetic force into the coil and port 3 is sealed and ports 1 and 2 are connected together.

57 The different modes of powering a solenoid valve. Standard AC (alternating current) solenoids are built to operate using a cyclic sine wave power input such as that detailed below. AC Cyclic Sine Wave All DC (Direct Current) solenoids operate using a smooth power such as the wave form below. DC power is polarized while AC power is not. DC Smoothed Wave Some AC solenoids are in fact DC solenoids which use AC power which is converted within the solenoid to DC by wave rectification using diodes. AC Cyclic Sine WaveDC Smoothed Wave converted to

58 There are two types of AC solenoid valves used in the irrigation industry. 1. The standard AC solenoid valve. 2. The DC solenoid valve which uses AC power that is converted through rectification to DC Both of the above solenoids require power continuously, during operation. The different modes of powering a solenoid valve. There are also two types of DC solenoids is use. 1. The standard DC solenoid (seldomly used in irrigation applications.) 2. The magnetic latch DC solenoid. The standard DC solenoid requires power all the time during operation. The magnetic latch solenoid switches from one position to the other by receiving an electrical pulsed signal. The plunger is held in position by the magnet. It is possible to have either 2 wire AC Solenoid Valves DC Solenoid Valves Standard 24 volt AC solenoid coil 3 wire DC magnetic latch solenoid coil 2 wire DC magnetic latch solenoid coil Magnet or 3 wire DC magnetic latch solenoid operators.

59 The different modes of powering a solenoid valve. Some important differences between AC and DC powered solenoids. DC power cannot be conveyed effectively over long distances and therefore AC power is the preferred source in larger systems. As DC power is polarized, it has a tendency to cause electrolysis at poor joins underground which results in corrosion and joint breakdown. This problem is not as apparent in AC systems. AC power is not as effective as DC in the operation of the solenoid. The cyclic power supply is the main cause of this. Many companies have thus a preference to using DC coils. DC solenoids have no inrush current. This includes solenoids that use AC power which is converted to DC within the solenoid itself.When calculating the wire sizes for standard AC solenoids, it is important to take the extra inrush load required during initial activation into consideration. This is not required in DC solenoids. DC magnetic latch solenoids require a minimum amount of power and are therefore very effective for battery and solar operated systems.

60 Commonly used solenoid valves.

61 A few examples of commonly used solenoids in the irrigation trade. 24 Volt AC 3 Way solenoid and Base 9/12 Volt DC Latch 3 Way solenoid and Base Heavy Duty 24 Volt AC 3 Way solenoid and Base

62 The difference between a 2 way and a 3 way solenoid. 2 way solenoids. 2 Way solenoids are used on internally ported single chamber hydraulic control valves, mainly on plastic moulded valves. 2 Way solenoids are not complete valves as they do not allow for the flow of water through the solenoid. 2 Way solenoids are only available in normally closed configuration. 3 Way solenoids are used on externally plumbed hydraulic control valves. 3 Way solenoids once fitted with a valve base become 3 way solenoid valves. 3 Way solenoid valves are available in Normally Open and Normally Closed configuration. 3 way solenoids. A typical 2 way solenoid operator. A typical 3 way solenoid operator.

63 The difference between normally open and normally closed solenoid valves. Normally Open Solenoid Valves. Port 3. De-activatedActivated Port 1. Port 2. A normally open solenoid valve will open the valve controlled by the solenoid, when the solenoid is energized. The relationship between the size of the hole marked "A" in port 3, the water pressure at this hole and the pulling force of the solenoid on the plunger when activated, determines the solenoids maximum operating pressure. The higher the force the plungers seal exerts on the hole, the higher the pressure at port 3, can be. A B Port 1 - Vent / Exhaust Port 2 - Common Port 3 - Pressure To assist this action, the spring at "B" needs to be relatively soft. The larger the hole at "A" the lower the shutoff pressure can be in port 3. Most solenoids used in the irrigation industry are rated to operate at 10 Bar. The normally open solenoid valve is the most popular in the irrigation industry.

64 The difference between normally open and normally closed solenoid valves. Normally Closed Solenoid Valves. Port 3. De-activatedActivated Port 1. Port 2. A normally closed solenoid valve will close the valve controlled by the solenoid, when the solenoid is energized. A B Port 1 - Pressure Port 2 - Common Port 3 - Vent / Exhaust The relationship between the size of the hole marked "A" in port 1, the water pressure at this port and the pushing force of the solenoids plunger when de-activated, determines the maximum operating pressure of the solenoid valve The higher the force the plungers seal exerts on the hole, the higher the pressure at port 1 can be. To assist this action, the spring at "B" needs to be relatively strong. The larger the hole at "A" the lower the shutoff pressure can be in port 1. Most solenoids used in the irrigation industry are rated to operate at 10 Bar. The normally closed solenoid valve is not commonly used in the irrigation industry.

65 3 Way Ball Valve Pressure Selector Tee The three way ball valve used in three way systems. One common port is connected to one of the other three ports as selected by the operator. The inline two way ball valve is used for two way systems. This valve is a simple Open or Closed, 90 degree turn ball valve. Needle valves are used for pinching the control passage within the control network. The selector tee is generally used in three way systems and will only allow water to flow from one of the ports through the common port at any given time depending on which port has the higher pressure.. Inline spring loaded non return valves are used in two and three way system. Often used to convert the control valve into a check valve.

66 Hydraulic Fittings Finger Filters Control network filters Finger filters - Available in brass and plastic in sizes 1/4m x 1/4f or 1/4m x 1/8f. Both long and short versions are available in brass. Long finger filters are used for 150mm valves and upwards. Inline Filters - Available in brass or plastic in 1/2" and 3/4" sizes. Used mainly on two way systems. Fittings Plastic Fittings - A full range of fittings including, elbows, connectors, adapters, tees and nipples. Available in 8mm, 6mm, 1/4" or 1/8" connections. Brass Fittings - A full range of fittings including, elbows, connectors, adapters, tees, nipples, sockets, etc. Available in 1/4" or 1/8"

67 Manual Open/Close Valve (3 Way Operation) C A OC A OC A O Overview The valve is controlled manually by a three port selector valve which allows the user to select the "Closed" position, "Open" position or the "Auto" position for remote control operation. The control of the valve is effected effortlessly and quickly, even under high operating pressures. Applications. Activation of valves located in inaccessible places. Activation of valves remote from the control. Effortless activation of large valves. Design Considerations. Size the valve to suite: The maximum flow rate The maximum allowable head loss The maximum allowable velocity C = Closed O = Open A = Automatic ClosedOpenRemote

68 Electric Open/Close Valve with Manual Override (3 Way Operation) Applications. Electrically activated remote control valve. Design Considerations. Electric valves can be Normally open or Normally closed. This term refers to the valve and not the solenoid. Valves operating at high pressures require non standard solenoids. If water is abrasive or dirty use a hydraulic relay or consider improving control network water filtration. 1 2 1 2 1 2 1 2 A.B.C.D. Overview The valve is controlled by an electrical solenoid valve which converts an electrical command signal into a hydraulic or pneumatic command. Operating Position. A - Solenoid is inactive, valve is closed B - Solenoid is active, valve is open C - 3 Way selector valve is set to manual close, valve is closed. D - 3 Way selector valve is set to manual open, valve is open. 1 is a normally open 3 way solenoid valve 2 is a 3 way selector valve

69 Hydraulic Remote Controlled Open/Close Valve (3 Way Operation) Remote CommandNo Remote Command 11 1 is a 3 way hydraulic relay Closed Open Applications. Control of remotely located valves form a common point when electricity is not available or is problematic. Design Considerations. Relays are generally recommended when the distance between the valve and the control position exceeds 100m. Smaller remote control tubes are advised to hasten the activation of the relay. The remote source must be equal or higher than the pressure at the valve. Overview The valve is fitted with a hydraulic relay which converts a remote pressure signal to a local hydraulic command, thus accelerating the valves response. Relays are often also used to overcome elevation problems when the remote source is higher than the valve location. The relay needs to be equipped with the correct spring for this function. Operating Position. Closed - No remote signal is provided so the valve uses local pressure to close. Open - A remote signal is applied and the valve vents locally to open.

70 Non Slam Check Valve Overview The valves upper chamber is connected hydraulically into the downstream. When the upstream pressure falls below that of the downstream, the valve closes immediately preventing the reverse flow in the network. The flexible diaphragm ensures soft closure, protecting the network from the damaging effects of water hammer. The closing speed of the valve is adjustable by setting the needle valve. Applications. Preventing drainage of uphill pump networks. Design Considerations. This type of valve closes slower than a conventional check valve and therefore some form of reverse flow can be expected before the valve is fully closed. This type of check valve has considerable head loss and therefore it should be used mostly on two way operating valves. If head loss of 10 Mts. is unacceptable, another solution should be sought. 1 is a Needle Valve 1. ClosedOpen

71 Pressure Reducing Valve (2 Way Operation) A. B. Applications. Control of network pressure in industrial, water supply, high rise buildings and agricultural systems. Design Considerations. Valves fitted with two way operating systems create pressure loss regardless of flow. Two way operation should only be utilized when the required loss is greater than 10 Mts. under all operating conditions. When the required reduction over the valve is high and the flow rate is low, it is advisable to install a smaller bypass valve in parallel with the larger valve. Beware of cavitation and reduction ratios. Overview The valve reduces high upstream pressure to create a lower, stabilized downstream pressure. The pressure reducing valve will accurately control downstream pressure regardless of upstream pressure or flow rate fluctuation. This valve will also provide pressure control under no flow conditions Operating Position. A - The valve will close when the downstream pressure exceeds the pre-set limit on the pilot. Complete closure will occur under shutoff conditions B - The valve will open until the sensed downstream pressure is equal to or greater then the pilots set pressure. C - Under normal operation, the valve is in the regulation mode. C. 1. 2. 1. 2. 1. 2. 1 is a needle valve 2 is a two way pilot valve

72 Pressure Reducing Valve (3 Way Operation) A. B. Applications. Pressure control mainly used in agriculture low pressure networks. Pressure control in low pressure pumping systems with fluctuating flows. Design Considerations. The three way system should be selected in systems where minimal or zero pressure differential is required under certain operating conditions. The response time of a valve fitted with 3 way control can be delayed and it is advisable to consider the installation of a quick relief valve, downstream of the PRV, to protect the system. Do not use the three way control system when no flow conditions are envisaged. Beware of cavitation. Overview. The valve reduces high upstream pressure to create a lower, stabilized downstream pressure. When upstream pressure decreases to the required downstream pressure, the valve opens fully. Minimal friction loss is created. Operating Position. A - The downstream pressure exceeds the pilots setting, causing the valve to partially close to reduce the downstream pressure. B - The downstream pressure is lower than the set level causing water to be vented form the control chamber, opening the valve. C - The upstream pressure is lower than the pilots setting causing the valve to open fully. D - The downstream is balance with the set pressure causing the pilot to close. The valve will remain in this position. C. D. 1. 1 is a 3 Way Pressure Reducing Pilot Valve.

73 Pressure Sustaining Valve (3 Way Operation) Applications. Limiting the flow in downhill networks. Downstream of high elevation areas to ensure sufficient pressure is available to these areas. As a relief valve to relieve excess pressure out of the system. Design Considerations. Sustaining valves are fitted into the pipeline where relief valves are fitted on a tee junction to relieve water from the system. The response time of a valve fitted with 3 way control can be delayed when changing from the fully open position. A sustaining/ relief valve is not suitable to protect the system against shutoff conditions. Use a quick relief valve for system protection Beware of cavitation. Overview The valve remains closed while upstream pressure is below the pre-set pressure on the pilot. When the upstream pressure increases the pilot limits the valve opens to a position keeping the required set upstream pressure. The pilot allows the valve to open fully when upstream pressure exceeds the pilots setting. Operating Position. A - The upstream pressure is lower than the pre-set level of the pilot causing the valve to close. B - The upstream pressure increases to the pre-set level of the pilot allowing the valve to open partially. C - The upstream pressure is equal to that of the pilots setting causing the pilot to close and locking the valve in this position. D - The network pressure is higher than the pilot pre-set pressure causing the valve to open fully. 1 is a 3 Way Universal Pilot Valve. A. B.C. D. 1.

74 Quick Pressure Relief Valve (2 Way Operation) Applications. Preventing pressure surges in the system. Design Considerations. Relief valves are not modulating valves and must not be used for this purpose. A quick acting pressure relief valve should be selected to discharge between 50 - 80% of the systems nominal flow. The following valve selection is recommended for short periods of flow. 50mm valve up to 100 m³/hr 65mm valve up to 160 m³/hr 80mm valve up to 250 m³/hr 100mm valve up to 400 m³/hr 150mm valve up to 850 m3/hr Overview The valve is mounted on a tee junction in the network and adjusted to open instantly whenever the network pressure exceeds the pre-set pressure of the pilot. This valve therefore protects the network from dangerous pressure surges. The needle valve allows for adjusting the closing speed of the valve. Operating Position. A - The pressure in the network is below the pilots setting. The valve remains closed. B - The network pressure exceeds the pilots setting causing the valve to open instantly. Full opening is achieved. C - The network pressure falls below the pre-set level of the pilot and the valve begins to close. Speed of closure is dependent on the needle valve setting. 1 is a Needle Valve 2 is a Quick Relief Pilot Valve. A. B.C. 1.2.1.2.1.2.

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76 Needle valve to adjust the valves closing speed. 68-500 Brass Pilot Valve BACK Basic Valve with Quick Acting Brass Pressure Relief Pilot – 2 Way IN OUT CLOSE

77 68-500 Brass Pilot Valve BACK Basic Valve with Quick Acting Brass Pressure Relief Pilot – 2 Way IN OUT OPEN

78 Needle valve to adjust the valves closing and opening speed. 2WPR Brass Pilot Valve BACK OPEN Basic Valve with Brass Pressure Reducing Pilot Valve – 2 Way IN OUT

79 Needle valve to adjust the valves closing and opening speed. 2WPR Brass Pilot Valve BACK CLOSE Basic Valve with Brass Pressure Reducing Pilot Valve – 2 Way IN OUT

80 2WPR Brass Pilot Valve BACK REGULATE Basic Valve with Brass Pressure Reducing Pilot Valve – 2 Way IN OUT

81 Com. Closed Auto Open InOut Sense Basic Valve with Manual Override, Universal Pilot fitted for reducing operation, 3 way Universal Pilot 3WUI Brass Pilot Valve If the downstream pressure is LOWER than the spring tension, the valve will OPEN. BACK

82 Com. Closed Auto Open InOut Sense Basic Valve with Manual Override, Universal Pilot fitted for reducing operation, 3 way Universal Pilot 3WUI Brass Pilot Valve If the downstream pressure is HIGHER than the spring tension, the valve will CLOSE. BACK

83 Com. Closed Auto Open InOut Sense Basic Valve with Manual Override, Universal Pilots fitted for reducing operation, 3 way 3WUI Brass Pilot Valve If the downstream pressure is EQUAL to that of the spring tension, the valve will be in the REGULATED position. Fluid locked in upper chamber in regulated mode. REGULATION BACK

84 XR 100 - Plastic Pilot Valve Basic Valve with Pressure Reducing Pilot Valve (Built in Manual Override) – 3 Way. 2 3 4 1 5 OpenClosed Auto MANUALLY CLOSED BACK

85 XR 100 - Plastic Pilot Valve Basic Valve with Pressure Reducing Pilot Valve (Built in Manual Override) – 3 Way. 2 3 4 1 5 OpenClosed Auto MANUALLY OPEN BACK

86 XR 100 - Plastic Pilot Valve Basic Valve with Pressure Reducing Pilot Valve (Built in Manual Override) – 3 Way. 2 3 4 1 5 Remote signal from solenoid valve at RX unit, etc. AUTO CLOSED OpenClosed Auto BACK If the remote signal is weak, use the RCU (Remote Command Unit) (below 3 Bar)

87 XR 100 - Plastic Pilot Valve Basic Valve with Pressure Reducing Pilot Valve (Built in Manual Override) – 3 Way. 2 3 4 1 5 AUTO OPEN OpenClosed Auto Remote signal from solenoid valve at RX unit, etc. BACK

88 XR 100 - Plastic Pilot Valve Basic Valve with Pressure Reducing Pilot Valve (Built in Manual Override) – 3 Way. 2 3 4 1 5 REGULATION IN AUTO OPEN OR MANUAL OPEN POSITIONS Remote signal from solenoid valve at RX unit, etc. If the downstream pressure is LOWER than the spring tension, the valve will OPEN. BACK

89 XR 100 - Plastic Pilot Valve Basic Valve with Pressure Reducing Pilot Valve (Built in Manual Override) – 3 Way. 2 3 4 1 5 Remote signal from solenoid valve at RX unit, etc. REGULATION IN AUTO OPEN OR MANUAL OPEN POSITIONS If the downstream pressure is HIGHER than the spring tension, the valve will CLOSE. BACK

90 XR 100 - Plastic Pilot Valve Basic Valve with Pressure Reducing Pilot Valve (Built in Manual Override) – 3 Way. 2 3 4 1 5 Remote signal from solenoid valve at RX unit, etc. REGULATION IN AUTO OPEN OR MANUAL OPEN POSITIONS If the downstream pressure is EQUAL to that of the spring tension, the valve will be in the REGULATED position. BACK Fluid locked in upper chamber in regulated mode.


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