1. For the interconnection of pneumatic components and systems
Fittings and Tube
For the interconnection of pneumatic components and systems 1

2. Contents Introduction Presentations Thread sizes Pneufit
Tube sizes and materials
Push-on fittings
Fitting types
External nut compression
Industry specific fittings
Internal nut compression
General purpose fittings
BSP and Hose fittings
Function fittings
FleetFit (vehicle fittings)
Standards
WeldFit (welding industry )
Sealing the thread
Plasfit (brewing industry)
Taper and parallel
Tube and Hose
Pressures / temperatures
Click the section or presentation to go to it

3. Introduction
Fittings connect the components of a pneumatic system with flexible tubing, hose and rigid pipe
A variety of fittings ranges are produced to fulfil the needs of general and specific industries
The variables include:
methods of connection
thread sizes
tube sizes
angles of connection
number of connections
materials of construction
applications
industry standards

4. Thread sizes
For the majority of pneumatic applications fittings will be required in the ranges:
R 1/8 , R 1/4 , R 3/8 , R 1/2 , R 3/4
M 5, G 1/8 , G 1/4 , G 3/8 , G 1/2 , G 3/4 , G 1
NPTF 1/8 , 1/4 , 3/8 , 1/2

5. Tube sizes Tube sizes are identified by their o/d (outside diameter)
The metric range covers 4, 5, 6, 8, 10, 12, 14, 16, 22, 28 mm o/d
The inch range covers 1/8 , 5/32, 3/16, 1/4, 5/16, 3/8, 1/2, 5/8, 3/4 o/d

6. Tube and hose materials
Plastics
Polyamide ( Nylon )
Nylon, food grade
Polyurethane
Terylene braided PVC
Metal braided rubber
Weld tube
Copper
Annealed
Half hard standard duty
Half hard heavy duty
Steel
Double wall brazed

7. Types of Pneumatic Fittings
Push-In Fittings, very quick joint with the tube
Push-On Fittings, neat, quick joint using a finger tight nut
Compression Fittings, firm joint, for plastic or metal tube:
internal nut version
external nut version

8. Industry specific fittings
Plasfit, hygienic, food grade plastic push in fittings designed for use in drinks dispense and brewing industries
FleetFit, brass push-in fittings with tube support, for vehicle air braking systems and auxiliary systems
WeldFit, nickel plated brass push-in fittings with tube support, for use with WeldTube to protect against damage from weld spatter.
8 m m 5

9. General purpose fittings
BSP and Hose taper and parallel fittings
Nickel plated brass construction
Adaptors
Connectors
Reducers
Expanders
Bulkheads
Tees
Elbows
Unions
Hose connectors
Banjos

10. Function fittings Pneumatic sensor Blocking Pressure reducing
Senses the falling exhaust pressure in an actuator and sends a signal when it has stopped
Blocking
Activated by removing a pneumatic pilot signal to block flow one way
Pressure reducing
Placed in the line to one end of a cylinder to reduce pressure 2 1

11. Thread standards (Europe)
Fittings
Taper male threads comply with ISO 7 (BS 21) and are designated by R 1/8 , R 1/4 , R 3/8 , R 1/2 etc.
Parallel male and female threads comply with ISO 228 (BS 2779) and are designated G 1/8 , G 1/4 , G 3/8 , G 1/2 etc.
Parallel metric threads are to ISO 261 (BS3643) designated M5x1, M10x1, M12x1.5, etc.
Ports
The ports in components such as cylinders and valves are parallel and comply to ISO 228 (BS2779) these are designated G 1/8 , G 1/4 , G 3/8 , etc.
Parallel metric threads are to ISO 261 (BS3643) designated M5x1, M10x1, M12x1.5, etc.

12. Thread standards (USA)
Fittings
Dryseal threads are taper male threads NPTF “National (American) Standard Pipe Taper Fuel and Oil”
Sizes show TPI (threads per inch). The most popular range for industrial pneumatics are 1/8 -27, 1/4 -18, 3/8 -18, 1/2-14, 3/4 -14
Ports
The ports in components such as cylinders and valves are NPTF. This provides a male taper to female taper joint.
NPSF and NPSI parallel female threads also allow connection with male taper NPTF fittings

13. Sealing the thread
Parallel threaded fittings seal on a washer between the fitting and the face of the component’s port. The surround to the port is usually spot face machined
Taper threaded fittings rely on a lightly wedged fit and use sealant between the threads of the fitting and port

14. Taper to parallel
Taper fittings are made smaller in diameter as there is no bearing surface required for a washer
Taper fittings do not require the port to be spot faced so are suitable for ports in unmachined components and ports at an angle to their surface
By manufacturing to selected tolerances taper fittings are successfully used with parallel ports
This combination is very popular in many sectors of the pneumatics industry
Fittings must not be over tightened, particularly for ports in thin wall cast material as there is a risk of cracking the casting

15. Working pressure ranges
The safe working pressure for the majority of pneumatic systems is 10 bar maximum with some components up to 16 bar maximum
Most fittings will be safe at pressures in excess of these but obtain advice
Plastic tubing is limited by wall thicknes and operating temperature
Metal tubing has a higher rating
Pressure Max from Vacuum
Pneufit 18 bar *
FleetFit 10 bar
WeldFit 18 bar *
Plasfit 10 bar
Limited by plastic tube
Push-on 9 to 11 bar
Compression 15 to 28 bar * If tubing allows and not including regulating banjos which are 10 bar
Tubing details

16. Working temperature ranges
Temperatures are generally limited by the plastic and rubber parts of a fitting and the tube material
For extreme temperatures use compression fittings and metal tube. Also choose taper threads
Where parallel threaded fittings are supplied with plastic washers the temperature is limited to - 40OC to 70OC
Push- in Range
Pneufit -200C to 700C
Plasfit 00C to 700C
Fleetfit C to 1000C
Weldfit C to 700C
Push- on
24 Series 0OC to 70OC
Compression fittings with metal tube at 10 bar
- 40 to +100OC
BSP and Hose
limited by tube or hose

17. End

19. Pressure rating Plastic tube O/D mm 4 5 6 8 10 12 14 16 22 28
bar maximum
Polyamide (PA) 28 31 25 19 24 18 15 18 15 15
Polyurethane (PU) 10 11 10 9 9 9
Pressure values are for a temperature range -40 OC to +20 OC
For compressed air above 16 bar consult our technical service
Higher temperatures OC
Pressure adjustment factor

20. Pressure rating Copper and steel tube O/D mm 4 5 6 8 10 12 16 22 28
bar maximum
Copper Annealed
128
138
112 81 64 81 59 53 41
Copper Half Hard
193
208
218
157
150
122 89 81 62
Steel
300
250
195
160
Pressure values are for a temperature range -40 OC to +50 OC
For compressed air above 16 bar consult our technical service
Pressure adjustment factors OC
Annealed
100
Half Hard
150
175
200
0.97
0.82
0.63
0.43
0.95
0.88
0.54
0.29

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