Diaphragm Valve Materials of Construction

DIAPHRAGM VALVE BODY PATTERN AND MATERIAL OPTIONS

VALVE BODY MATERIALS

CAST IRON: ASTM A-126
Cast Iron is a general purpose material suitable for water, air, petroleum products, most solvents, dry powders, and a wide variety of chemicals when used in the unlined state. Cast iron can be lined with a wide variety of rubbers and plastics to handle almost any process media.

DUCTILE IRON: ASTM A-536-GR 65-45-12
Ductile Iron is a general purpose material with usage similar to cast iron. However, it is much stronger and more capable where there may be high pipeline stresses, danger from impact, or concern from leakage upon line or valve fracture. Normally ductile iron can be used as a direct replacement for steel valves. It can be lined with a wide variety of rubbers and/or plastics to handle almost any process media.

CAST STEEL: ASTM A-126 GR WCB
Cast Steel is another general purpose material somewhat less resistant to corrosion than cast iron, especially where water is the media. It is much stronger, and like ductile iron, much more capable where there may be high pipeline stresses, danger from impact, or concern from leakage upon line or valve fracture. Cast steel valves are expensive and are normally only used where specified by the end user. Cast steel valves can be lined with a wide variety of rubbers and/or plastics to handle almost any process media.

316 STAINLESS STEEL: ASTM A-351 GR CF8M
316 Stainless Steel is an alloy of iron, carbon, nickel, and chromium. It is suitable for most foods, beverages, pharmaceuticals, solvents, sea water, oils, and some acids and alkalis.

ALLOY 20 STST: ASTM A-351 GRADE CN-7M
Alloy 20 Stainless Steel has higher amounts of nickel and chromium than the 300 Series Stainless Steel. It is more resistant to sulfuric acid and is widely used in chemical processing and water treatment.

NOTE: Additional body materials are available, contact Tru-Tech Valve for details.

DIAPHRAGM MATERIALS AND ACCESSORIES

DIAPHRAGM MATERIALS

ETHYLENE PROPYLENE (EPDM): -30° F to 300° F
EPDM is the most popular general purpose material. It possesses excellent chemical resistance to a wide variety of corrosive elements including acids, caustics, and hot water. EPDM is abrasion resistant, good for high temperature service, and is satisfactory for intermittent steam sterilization, but has poor oil resistance.

NEOPRENE (CR): -20° F to 200° F
Neoprene is widely used in wastewater applications. It is a good choice for general purpose chemical resistance
where the media contains entrained oils. It is abrasion resistant, and also resists aldehydes, certain alcohols, fertilizers, explosives, petroleum, air, acids, and alkalis.

SOFT NATURAL RUBBER (NR): -30° F to 180° F
Soft Natural Rubber is good in either wet or dry abrasive services, water, and some acids and alkalis. It has one of the best abrasion resistances when strong chemicals are not present.

VITON® (FKM): -20° F to 300° F
Viton offers exceptional resistance to oils, most chemicals, and many solvents at elevated temperatures. It can be used in most applications involving mineral acids, salt solutions, and chlorinated hydrocarbons. Viton is not recommended for ammonia, its derivatives, or polar solvents, e.g. acetone.

TEFLON® TFE/EPDM: -30° F to 300° F
TFE is the most chemical resistant of all the diaphragm materials. It is good for handling strong acids, alkalies (caustics), and solvents. Because of its greater stiffness, it significantly increases required closing/sealing forces. TFE has a shorter working life than elastomer diaphragms and may require a larger actuator size on automatic valves.

BUTYL: -20° F to 250° F
Butyl is a good choice for gases because it has very low vapor and gas permeability. It is also good for many acids, alkalis, and applications involving steam sterilization.

® - Registered Trademarks of E.I. Dupont Corporation
NOTE: Additional diaphragm materials are available, contact Tru-Tech Valve for details

ACCESSORIES

Tru-Tech Valve offers a wide range of accessories. To find out more, contact our Sales Department for details.
P/P Positioners
I/P Positioners
Limit Switches
Proximity Switches
Regulators
Solenoids
Travel Stops

DIAPHRAGM VALVE BODY BODY LININGS

SOFT NATURAL RUBBER: Soft Natural Rubber is good in either wet or dry abrasive services, water, and some acids and alkalis. It has one of the best abrasion resistances when strong chemicals are not present. Temperature range is from -30° F to 180° F.

HARD RUBBER: Hard Rubber is a good general chemical resistant lining that can be used in higher temperatures than its soft counterpart. Temperature range is from -30° F to 200° F.

GRAPHITE BASED HARD RUBBER: Graphite Based Hard Rubber has a good chemical resistance at higher temperatures than the normal hard and soft natural rubbers. Maximum use temperature is 250° F.

EPDM: (Ethylene Propylene Diene Monomer) EPDM is the most popular general-purpose material. It possesses excellent chemical resistance to a wide variety of corrosive elements including acids, caustics, and hot water. EPDM is abrasion resistant, good for high temperature services, and is satisfactory for intermittent steam sterilization, but has poor oil resistance. Temperature range is from -30° F to 300° F.

NEOPRENE: Neoprene is widely used in wastewater applications and is a good choice for general-purpose chemical resistance where the media contains entrained oils. It resists aldehydes, certain alcohols, fertilizers, explosives, petroleum, air, acids, and alkalis, and is abrasion resistant. In most cases, Neoprene is interchangeable with Buna-N (Nitrile) Rubber. Temperature range is from -30° F to 200° F.

BUNA-N: (Nitrile Butadiene Rubber) Buna-N is a general-purpose oil resistant polymer known as Nitrile Rubber. It is a copolymer of butadiene and acrylonitrile. Buna-N has good resistance to solvents, oil, water, and hydraulic fluid. It displays good compression set, abrasion resistance, and tensile strength. Buna-N should not be used in highly polar solvents such as acetone and methyl ethyl ketone, nor should it be used in chlorinated hydrocarbons, ozone, or nitro hydrocarbons. In most cases it is interchangeable with Neoprene. Maximum use temperature is 275° F.

BUTYL: Butyl is a good choice for gases because it has very low vapor and gas permeability. It is also good for many acids, alkalis, and applications involving steam sterilization. Temperature range is -20° F to 250° F.

CHLOROBUTYL: Chlorobutyl has excellent abrasion and corrosion resistant properties. Maximum recommended temperature is 180° F.

POLYPROPYLENE: Polypropylene is a general purpose lining with good chemical and temperature resistance. It is utilized for water treatment, chemical processing, most plating fluids, steel mill pickling lines, food stuff, and drinking water. Temperature range is from -10° F to 200° F.

ECTFE (HALAR): (Ethylene Chlorotrifluoroethylene) ECTFE has excellent wear and abrasion qualities, excellent corrosion resistance, excellent electrical properties, and low coefficient of friction. Maximum use temperature is 350° F.

ETFE (TEFZEL): (Ethylene Tetrafluoroethylene) ETFE has outstanding resistance to chemicals and strong acids. It also has high abrasion resistance for tough services. ETFE has no known solvent below 350° F.

DIAPHRAGM VALVE BODY LININGS

PTFE (XYLAN): (Polytetrafluoroethylene) PTFE has good wear resistance, fair corrosion resistance, and low coefficient of friction. Temperature range is from 450° F to 500° F.

PFA: (Perfluoroalkoxy) PFA has good wear and abrasion qualities, excellent corrosion resistance, excellent release capabilities, and low coefficient of friction. Maximum us temperature is 525° F.

PVDF (KYNAR): (Polyvinylidene Fluoride) PVDF offers very low permeability. It is a strong, tough, abrasion resistant fluorocarbon material, resistant to most acids, bases, and organic solvents. PVDF is ideally suited to handling wet or dry chlorine, bromine, and other halogens. Temperature range is from -10° F to 275° F.

FEB: (Fluorinated Ethylene Propylene) FEB has good wear and abrasion qualities, excellent corrosion resistance, excellent release characteristics, and low coefficient of friction. Maximum use temperature is 400° F.

BLUE GLASS (CHEM): Blue Glass is intended for strong chemical applications such as acids and caustics where a non-porous lining is necessary.

GREEN GLASS (NON-CHEM): Green Glass is intended for non-chemical applications such as wastewaters where a smooth lining is necessary to prevent viscous fluids from sticking to the walls.

POLYURETHANE: Polyurethane has excellent abrasion resistance. Temperature range is from -30° F to 150° F.

FDA EPOXY: FDA Epoxy has good wear and abrasion qualities, and good corrosion resistance. Maximum use temperature is 212° F.

PVC: PVC has resistance to a variety of chemicals, including oxidizing acids, and provides excellent abrasion resistance. Maximum use temperature is 160° F.

® - Registered Trademarks of E.I. Dupont Corporation
Note: Other body materials are available as an option; call our Sales Department for details.