MATERIALS
Valve materials of construction can be very varied, ranging from metals to alloys to plastics. We will list the most common ones together with their most commonly used abbreviations.
AL Aluminium
BR Brass
BRZ Bronze
CI Cast Iron
CR Polychloroprene, Neoprene
CS Cast Steel
CSM Chlorosulphonated Polyethylene, Hypalon
DI Ductile Iron
EPDM Ethylene Propylene Propylene Diene Monomer
FKM Fluorinated Propylene Monomer, Viton
NBR Nitrile Butadiene Rubber
NR Natural Rubber
PE Polyethylene
PEEK Polyetherether Ether Ketone
POM Polyoxymethylene
PP Polypropylene
PPG Polypropylene Glycol
PTFE Polytetrafluoroethylene
PVC Polyvinyl Chloride
PVDF Polyvinylidene Fluoride
RTFE Reinforced PTFE 15% Glass Fiber
SBR Styrene Butadiene Rubber
SS Stainless Steel
In valve construction it is very common to use different materials between the body and the trim.
Materials are also used differently:
FOUNDRY AND FORGE
CASTING
Most of the materials used in the construction of valves, whether for bodies or covers, are usually cast metals.
The material such as iron, bronze, steel, etc. And is inserted into a mould to create the shape of the valve. Mixtures of different materials can also be made to obtain the alloys. Casting materials tend to have pores if the casting is not of good quality.
As usual, valves with relatively low pressure ratings are usually made of cast iron.
FORGE
It offers better technical features such as:
They have no pores, offer greater resistance to temperature and pressure, hardness, etc. Commercially as an example that I have always used is the manufacture of a sword, to define the difference between a forged material and a cast one. We start from a cast material made in a mould, it is beaten to improve the mechanical resistance, eliminating the possible pores of the material.
WELDED CONSTRUCTION
This type of valve is constructed in pieces and welded together.
This type of construction is generally used for very large valves where the investment in moulds is very expensive. They also give us the possibility to manufacture a single valve for a specific application. As always, the choice of the best material is based on the best cost/benefit.
These are the most common metallic materials for the construction of metallic valves, with their equivalents:
|
CASTING |
FORGE |
CHAPAS |
PIPES |
|
A216WCB |
A105 |
A516 GR.70 |
A106 GR.B |
|
A217WC1 |
A182 F1 |
A204 GR.A |
A335 P1 |
|
A217WC6 |
A182 F11 |
A387 GR.11 |
A335 P11 |
|
A217WC9 |
A182 F22 |
A387 GR.22 |
A335 P22 |
|
A217 C5 |
A182 F5 |
A387 GR.5 |
A335 P5 |
|
A217 C12 |
A182 F9 |
A387 GR.9 |
A395 P9 |
|
A217 CA15 |
A182 F6 |
A240 TP 410 |
|
|
A352 LCB |
A350 LF2 |
A516 GR.70 |
A333 GR.6 |
|
A352 LC2 |
A203 GR.B |
A333 GR.7 |
|
|
A352 LC3 |
A350 LF3 |
A203 GR.E |
A333 GR.3 |
|
A351 CF3 |
A182 F304L |
A240 TP 340L |
A312 TP 304L |
|
A351 CF3M |
A182 F316L |
A240 TP 316L |
A312 TP 316L |
|
A351 CF8 |
A182 F304 |
A240 TP 304 |
A312 TP 304 |
|
A351 CF8C |
A182 F347 |
A240 TP 347 |
A312 TP 347 |
|
A351 CF8M |
A182 F316 |
A240 TP 316 |
A312 TP 316 |
