Adca Training Part 3 This presentation is only a guideline, that can only be completed by a trained personel. Adca Steam Equipment www.valsteam.com Training.10.

Adca Training Part 3 This presentation is only a guideline, that can only be completed by a trained personel. Adca Steam Equipment Training.10 E 10.08

Training Contents Part 3 Pipeline Sizing – Water Hammer
Steam Trapping – Condensate Removal Part 4 Pressure Reduction Safety Relief Valves and Other Steam Valves Part 5 Control Valves Components of Control Valves Humidification

Saturated Steam Pipeline Capacities at Specific Velocities
MASS FLOWRATES OF SATURATED STEAM FOR DIFFERENT VELOCITIES IN PIPES DIN STANDARD Pm bar v m/s FLOWRATE Kgs / h DN 15 DN 20 DN 25 DN 32 DN 40 DN 50 DN 65 DN 80 DN 100 DN 125 DN 150 DN 200 DN 250 300 0.4 15 10 17 28 48 64 103 171 236 397 600 878 1476 2346 3319 25 29 47 80 107 285 393 662 1000 1464 2459 3911 5532 40 46 75 128 274 456 628 1058 1601 2342 3935 6257 8851 0.8 13 22 35 60 81 130 216 297 501 757 1108 1862 2960 4187 36 59 101 135 360 495 835 1262 1846 3103 4934 6979 58 95 161 346 575 792 1335 2019 2954 4964 7894 11166 1 14 24 39 67 89 143 238 327 552 1221 2052 3263 4615 111 149 396 546 920 1391 2035 3420 5438 7692 38 104 178 381 634 873 1472 2226 3256 5471 8700 12307 2 21 57 97 131 209 347 478 806 1219 1784 2998 4767 6743 162 218 348 579 797 1344 2032 2973 4996 7945 11238 56 93 152 259 557 927 1276 2150 3252 4757 7994 12711 17980 3 127 273 454 626 1055 1595 2333 3921 6235 8820 76 125 212 455 1043 1758 2658 3889 6535 10392 14699 73 122 199 339 728 1212 1669 2813 4253 6223 10456 16627 23519 4 34 92 157 211 337 560 771 1300 1966 2876 4833 7685 10871 94 154 261 351 561 934 1286 2167 3277 4794 8055 12809 18119 90 150 246 418 898 1494 2057 3467 5243 7670 12888 20495 28990 5 109 186 250 400 665 916 1544 2334 3415 5738 9125 12907 182 310 417 666 1109 1527 2573 3890 5692 9564 15208 21512 292 496 667 1066 1774 2443 4116 6224 9107 15302 24333 34420 7 53 88 144 244 328 525 1202 2026 3064 4482 7532 11977 16941 146 239 407 547 875 1455 2004 3377 5106 7470 12553 19961 28235 141 234 383 652 1399 2328 3206 5402 8170 11953 20084 31937 45176 8 98 160 366 586 975 1342 2261 5003 8407 13369 18911 163 267 610 976 1624 2237 3769 5700 8339 14012 22282 31518 427 727 977 1562 2599 3579 6031 9120 13342 22420 35651 50429 72 119 195 331 445 711 1184 1630 2747 4154 6078 10212 16239 22971 198 324 741 1186 1973 2717 4578/ 6923 10129 17021 27066 38285 191 317 519 884 1897 3157 4347 7325 11077 16207 27233 43305 61255 96 444 596 954 1587 2186 3683 5570 8150 13694 21776 30802 266 435 740 994 1590 2645 3643 6139 9284 13583 22823 36293 51336 256 425 696 1185 1591 2544 4233 5829 9823 14854 21732 36517 58068 82138 20 134 222 363 617 829 1326 2205 3037 5118 7740 11324 19027 30256 42798 223 369 604 1029 1381 2209 3676 5062 8530 12899 18873 31712 50427 71330 356 591 967 1646 2210 3535 5881 8099 13648 20639 30196 50740 80684 114128 Pm – Gauge pressure; V – Velocity.

Pipeline Sizing CORRECT If we did not size pipe work correctly
Steam and condensate pipelines can be sized using 2 methods. Velocity and Pressure Drop. Velocity is the method used 99% of the time. Velocity Should be sized on approx 25 m/s !!! Example: Flow = barg reducing to 1 barg 25 m/s 25 m/s CORRECT If we did not size pipe work correctly 90Km/h 405 Km/h INCORRECT

Water Hammer Moving water contains a great deal of energy because of it’s weight and velocity. When the slugs of condensate are suddenly stopped or reaches a change of direction , the energy of movement (kinetic energy) as to be dissipated in some way. Since condensate is being transported in a confined space (pipe), the energy will be transmitted to any obstacle in it’s path and into the walls of the space (pipe wall, fittings, valves, etc). The main conditions for the occurrence of water hammer in both steam and condensate lines are: - Presence of condensate - High live or flash steam velocity - Change of direction or obstruction in the line Condensate slugs Water Hammer

Strainer with hanging basket
Water Hammer Potential sources of water hammer: Riser Strainer with hanging basket Concentric reducer How to prevent water hammer: Steam valves should be opened slowly to gradually increase the condensate flow Install drain pockets with appropriate steam traps along the line Pipe design in such a way as to eliminate back flow (check valves may be necessary) In case of condensate lifting after the trap, there must be sufficient pressure to move it out Build separate condensate lines if condensate comes from different line pressures

Water Hammer Steam CORRECT INCORRECT Steam
On horizontal steam mains always use eccentric reducers with the flat at the bottom. Steam CORRECT Eccentric reducer INCORRECT Steam Concentric reducer

Drain Connections CORRECT INCORRECT
By fitting a drain pocket of similar pipe diameter the condensate will not be able to pass over it and will be collected and drained away. INCORRECT Fitting a small bore drain pipe to the bottom of a large pipe will not work very efficiently. The velocity of the steam will carry the water over the drain pipe and into the system.

Separators Separators are designed to efficiently remove the moisture from steam flow. Wet steam is steam containing a degree of water, and is one of the main concerns in any steam system. It can reduce plant productivity and product quality, and can cause damage to most items of plant and equipment. Whilst careful drainage and trapping can remove most of the water, it will not deal with the water droplets suspended in the steam. To remove these suspended water droplets, separators are installed in steam pipelines. S25 S16 SH25 The centrifugal type separator uses a series of fins to generate high-speed cyclonic flow. The velocity of the steam causes it to swirl around the body of the separator, throwing the heavier, suspended water to the wall, where it drains down to a steam trap installed under the unit.

Steam Traps The steam trap has the basic task of retaining steam in piping and process equipment while automatically permitting condensate and free air venting. Some rule of thumb: Indoors a trap set should be present on a steam main every m Outdoors a trap set should be present every 30 – 50m A trap set should be present at the base of any lift They also should be found before isolation and control valves, flowmeters and the base of separators Trap sets should always be present at the end of lines, suitable for condensate drainage and air venting

Thermostatic Bimetallic
Steam Traps Thermostatic Bimetallic Thermostatic bimetallic (operated by changes in fluid temperature) A bimetallic disc is a combination of two layers of metal with widely different coefficients of expansion, which are inseparably bonded together. One side of the disc has a large coefficient of expansion comparing with the other . In cold conditions the discs are completely flat (fig.1). When heated , they will bend because one of the layers expands more than the other (fig.2). When assembly in groups with the small coefficient of expansion against each other, they will lie flat in cold condition (fig.3), but become increasingly convex when the temperature increases (fig.4). Fig.1 Fig.2 Fig.3 Fig.4

Thermostatic Bimetallic
Steam Traps Thermostatic Bimetallic Thermostatic bimetallic (operated by changes in fluid temperature) By stacking a number of disc pairs over the valve stem (fig.5) an increase of the expansion is achieved. And when the temperature near the bimetal rises, the bending of the disc-pairs will bridge the valve clearance and makes the valve close. The temperature of saturated steam is determined by its pressure. In the steam space, steam gives up its enthalpy of evaporation (latent heat), producing condensate at steam temperature. As a result of any further heat loss, the temperature of the condensate will fall. A thermostatic trap will pass condensate when this lower temperature is sensed. As steam or hot condensate reaches the trap, the temperature increases and the trap closes. The closing force (F1) is caused by the steam temperature, the opening force (F2) by the steam pressure on the valve. The condensate temperature regulates the position of the valve. Valve Seat Bimetals Fig.5 Clearance Closing force Temperature F2 F1 Open force Pressure

Steam Traps Thermostatic Capsule
Thermostatic bimetallic (operated by changes in fluid temperature) Steam Hot condensate Condensate Air

Thermostatic capsule (operated by changes in fluid temperature) Start-up position: The membrane regulator contains a liquid having an evaporation temperature a few degrees below the saturation temperature of water. During shut down or start-up, i.e. if cold condensate is present, the liquid filling is completely condensed. The pressure in the capsule is lower than the service pressure. The membrane and the valve disc is forced in the open position. The trap remains open (fig.1) Fig.1 Valve Fig.2 Seat Closed position: With rising condensate temperature, the liquid filling starts to evaporate. The pressure in the capsule increases, the membrane and the valve disc is moved into the closing position. Just before the condensate has reached is saturation temperature, the valve is closed completely (fig.2)

Thermostatic capsule (operated by changes in fluid temperature) Steam Hot condensate Condensate Air

Thermostatic Steam Traps
Bimetallic or Capsule BM Series TH –TSS Series Advantages Disadvantages Advantages Disadvantages Mains drainage; Very robust, resist water hammer and frost; Used on high pressure applications; Free air discharge; Can be used on superheated steam; Makes use of some sensible heat. No application where water logging can be a problem; Does not react very quickly to changing conditions of pressure and flow. Mains drainage; Good for venting air; No adjustment needed for varying steam pressures. Can be slow acting which may cause water logging; High cycle times can cause premature capsule failure. Application Mains drainage, space heating pipes, steam tracing Mains drainage, calandar rolls, space heating pipes, High pressure applications. Steam tracing lines, thermostatic air vents.

Steam Traps Float & Thermostatic
Mechanical (operated by changes in fluid density) A float through a simple lever mechanism opens or closes the valve seat according to the condensate level in the trap. The opening is proportional to the condensate rate and it is not influenced by temperature or pressure. Discharge is modulating and does not interfere with automatic controls, if fitted. Air venting is ensured by a thermostatic element located in the steam space above the condensate level. After releasing the initial air, it remains closed until air or other non-condensable gases accumulate during normal running and cause it to open by reducing the temperature of the air/steam mixture. The thermostatic air vent offers the added benefit of significantly increasing condensate capacity on cold start-up. Steam Condensate Air

Steam Traps Inverted Bucket
Mechanical (operated by changes in fluid density) In the inverted bucket steam trap the operating force is provided by steam rising into an inverted bucket and causing it to float in the condensate with which the trap is filled. The upward movement of the bucket is converted through levers into a valve movement. The valve is held shut when the bucket is floating, due to the presence of steam and the valve is open when the bucket sinks due to the presence of condensate. A small vent hole on the upper part of the bucket provides air and steam discharge for bucket movement. Steam Condensate

Mechanical Steam Traps
Float & Thermostatic Inverted Bucket or FLT Series IB Series Advantages Disadvantages Advantages Disadvantages Can be used on all process applications; High capacities; Good for air venting; Good performance on very low differential pressures; Not disturbed by wide and sudden fluctuations of pressure. Can freeze in exposed position if not equipped with anti-freeze device; Can be susceptible to water hammer; Limitation on maximum pressure; Mains drainage Continuous steam systems; They can withstand reasonable water hammer; Can not air bind; Slowly air release; Can lose water seal and blow steam if wrongly installed; Can freeze in exposed position if not equipped with anti-freeze device; Application All heat exchangers applications, Mains drainage, continuous process installations. Jacketed vessels, heater coils, calander rolls etc.

Steam Traps Thermodynamic
Thermodynamic (operated by changes in fluid dynamics) When steam is supplied to the plant, disc is raised from it’s seat rings by incoming pressure allowing instant discharge of air and condensate. When condensate becomes hot enough flash steam is formed as it flows through the trap. The high velocity of this flash steam creates a low pressure area under the disc which draws it towards the seat and builds up pressure in steam chamber. The flash steam pressure in steam chamber acting on the full top area of the disc, forces it down against the pressure of the incoming fluid until it seats on inner and outer ring, closing the inlet and trapping pressure in the steam chamber. In due course, condensation in chamber decreases the pressure there, the disc is raised by incoming pressure and the cycle starts again. Steam Condensate

Thermodynamic Steam Traps Advantages Disadvantages DT 40 DT 42
Simple operation (just one moving part); Compact, light-weight; No adjustment need for varying steam pressures; Unaffected by water hammer. Blast action can damage equipment; Always pass a small amount of live steam; Not suitable for very low differential pressures; May air-bind if a lot of air reaches the trap quickly on start up; Not recommended on automatically controlled systems (intermittent condensate discharge) . Application Mains drainage

Other Steam Traps Labyrinth – not a true automatic steam trap
Orifice – not a true automatic steam trap Open Bucket – not common doing to expensive construction and low performance advantages

Which Steam Trap ? Questions to ask Steam pressure
Pressure before the trap Steam back pressure on trap (if any) Application it is being used on Is it superheated steam, if so what temperature Inside or outside Body material preference Pipeline connections Flow rate (mains drainage flow rate not required) If flow rate not known we need more information to calculate how much steam is used

Steam Locking and Air Venting
When the condensate is removed through a siphon or dip pipe, like in rotating drying cylinders, steam locking may occur. If this happen and while the steam trap is locked, condensate accumulation inside the equipment will delay the process or damage raw material and or equipment. To avoid this problem a trap is needed with a steam lock release valve (needle valve). The aperture of this valve will bleed the steam locked in the siphon pipe directly into the outside pipe. Since inverted bucket traps naturally bleed some steam trough the bucket hole, they can be used in some applications where steam locking exist, mainly if the equipment accept intermittent discharge steam traps. The large volume of air normally present in the cylinders and other equipment can delay the heating process even if a float and thermostatic trap is used, thus, a separate air vent is often still needed. SLR Steam Lock Release FLT17

Condensate Pump Sets Mechanical POP – Pressure Operated Pump Steam
A mechanical pump consists of a body shell, into which condensate flows by gravity. The body contains a float mechanism, which operates a set of changeover valves. Condensate is allowed to flow into the body, which raises the float. When the float reaches a certain level, it triggers a vent valve to close, and an inlet valve to open, to allow steam to enter and pressurise the body to push out the condensate. The condensate level and the float both fall to a preset point, at which the steam inlet valve shuts and the vent valve re-opens, allowing the pump body to refill with condensate. Check valves are fitted to the pump inlet and discharge ports to ensure correct directional flow through the pump. The cyclic action of the pump means that a receiver is required to store condensate while the pump is discharging Steam Condensate Air

Packaged ADCAMAT – POPK
Condensate Pump Sets Packaged ADCAMAT – POPK The POP-K packaged pump units can be used to lift or displace hot condensate and other liquids even in hazardous areas. A POP-K packaged unit comprises an Adcamat pump, a vented receiver and all auxiliary items, compactly mounted on a metal frame piped and ready for connection. Packaged units save time, work and site costs. In addition they ensure that installation of the pump is correct in every detail. Two or more units can be connected in parallel to cope with flow rates beyond the capacity of a single pump. Units operating with compressed air are also available.

Start-up Valve CDV CDV 32 condensate drain valve automatically drains condensate from steam systems during start-up. A compression spring inside the governor keeps the valve open if the appliance stays without pressure. As soon as the service pressure has reached the closing pressure to which the CDV has been adjusted, the valve closes due to the differential pressure. When the pressure drops below the closing pressure the Condensate Drain Valve opens by spring force Steam Condensate

Start-up Valve CDV Condensate Steam Manifold MAS-H Draining a steam main with an elevated condensate line.

Heat Demand (Steam Demand) Example 1
Equation for the calculation of heat (steam) demand, according to the properties of a heat exchanger: Known are the heat demand per hour or the heat exchanger heating capacity. (If the heating capacity is unknown there are some “ways” to determine it approximately (using the knowledge about steam systems and equipments). Since the accumulation of condensate may reduce the heating capacity, only the latent heat (r) shall be utilized for heating and not the sensible heat stored in the condensate. - Heat demand for the heat exchanger = Kcal/h - Steam pressure = 6 bar (r = 493,8 Kcal/h) Some allowance should be considered because of heat losses by radiation.

Equation for the calculation of heat demand, according to the properties of the fluid to be heated: Known is the time required for heating a given quantity of a product: - Product = water - Inlet temperature in the heat exchanger = 20ºC - Outlet temperature in the heat exchanger = 60ºC - Flow = 3750 Kg of water in 30 min. - Cp (water) = 1Kcal/Kg ºC With this it is possible now to determine the amount of steam!

Knowing the heat surface of the heat exchanger it is possible to determine the heat demand using the following formula: Where, A – Heat exchanger area K – Coefficient of overall heat transfer Δtlm – Mean Logarithm Temperature Difference or Δtm – Mean Temperature Difference ts – 165º (steam at 6 bar g) A = 3m2 *K = 800 Kcal/Kg/h ºC * Arbritrary value for demonstration purposes only. One must confirm it according with the equipment used.

How to Select a Steam Trap
For correct trap sizing, we need to know: - Condensate loads in Kg/h - Safety factor to be applied - Differential pressure - Maximum allowable pressure (max. system pressure) For the given example condensate load have been determined before. Depending on experience factors and particular application a safety factor can be applied. In this case we consider 2:1, so, 607,5Kg x 2 = 1215Kg/h. Differential pressure is the difference between the pressure before and after the steam trap.

How to Select a Steam Trap (Differential Pressure)
P5=1,2bar Condensate Steam P1=6bar Secondary flow 4 m P2=xbar Control Valve Heat Exchanger P4=0,44bar (4x0,11) P3=xbar

How to Select a Steam Trap (Differential Pressure)
P1 – Pressure on steam main (6 bar) P2 – Pressure after the control valve, assuming the pressure drop on the control valve (less 10% as example) P3 – Pressure before the steam trap, including pressure drop in the heat exchanger tube bundle (we consider 0,5 bar for this example) P4 – Pressure after the steam trap doing to the lift pipe (every 1m of lift reduces pressure differential by 0,1 bar; we may consider 0,11 to compensate pipe friction) P5 – Pressure on the condensate main (1,2bar) ΔP = Pressure before the trap(P3) – Back pressure (P4+P5)

How to Select a Steam Trap
The first choice for a heat exchanger steam trapping is the float & thermostatic steam trap. As the maximum pressure is not more than 6 bar the FLT17 series is suitable, and for a flow of 1215 Kg/h the size DN25HC ΔP4,5 bar discharge at 3,26bar differential pressure ≈ 2050Kg/h (extrapolating). Even if the pressure on the condensate main (P5=1,2bar) un-exist (during the start-up, for example) , the ΔP will not exceed the maximum permissible ΔP of the steam trap (ΔP=4,9 – 0,44 = 4,46 bar) and so, our selection can be: Adca FLT17- 4,5 DN25HC float and thermostatic steam trap.

Pump / Trap Modulated control of the steam supply causes wide changes in pressure differential. The pressure in the unit drained may fall to atmospheric or even lower. In some plants it is not recommended to introduce air into the steam heating space and so the use of vacuum breakers is not tolerated, besides, if the condensate lifts after the steam trap the vacuum breaker will not assist drainage. The solution in these situations is the use of a Pump / Trap combination.

Pump / Trap When the steam pressure is sufficient to overcome back pressure the trap operates. If the pressure decreases, the pressure operated pump start to operate removing the condensate by pumping trough the steam trap. Secondary flow Steam Control Valve Heat Exchanger Motive Steam Steam trap Float type Condensate

Air Venting On Steam Systems
During start up of a steam system the pipes are full of air, besides, further amounts of air and other non-condensable gases will enter the system together with the steam, even if in low proportions. As explained in Part 1, air barriers represent a length warming period and consequently reduction in plant efficiency and process performance. Automatic air vents for steam systems operate on the same principle as thermostatic steam traps and they should be placed above the condensate level in order that only air and steam mixtures reach them. TH13 A

Air Venting On Liquid Systems
Air and other incondensable gases removal from water (liquid) lines is crucial for a good system performance. The presence of air normally causes excessive noise, low system performance and corrosion. In extreme, air locks can even inhibit the normal operation of pumping system. As explained in Part 1 air also operates as a barrier to normal heat transfer efficiency. AE16 SS

Compressed Air Traps Liquid Drainers
Ball float compressed air and gas traps or liquid drainers are ideal devices to drain condensation from air and gas lines. A float through a simple lever mechanism opens or closes the valve seat according to the condensation level in the trap. The opening is proportional to the condensate rate and it is not influenced by temperature or pressure. A separate balance pipe connection is provided to prevent air binding. FA16 SS

Vacuum Breakers As explained in Part 1 the vacuum formation is present in all steam systems and it may destroy equipments by implosion (amongst other problems). Vacuum breakers protect plant and process equipment against vacuum conditions. A spherical ball which remain on it’s seat during normal operation (under pressure condition), is lifted off it’s seat in case of vacuum formation, and air is drawn into the equipment “breaking” the vacuum. For larger volume equipments a disk type spring loaded check valve or specific air vacuum valves can be specified. VB21

Complete Steam Diagram

Adca Training Part 3 This presentation is only a guideline, that can only be completed by a trained personel. Adca Steam Equipment www.valsteam.com Training.10.

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Adca Training Part 3 This presentation is only a guideline, that can only be completed by a trained personel. Adca Steam Equipment www.valsteam.com Training.10.

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