Gate Valve By Material

When selecting the valve material of the gate valve, the material should be determined according to the actual conditions of working conditions such as temperature, pressure & medium. The material of ZECO gate valve includes, but is not limited to stainless steel, carbon steel, forged and cryogenic.

Water, oil, natural gas, steam, and other non-corrosive media the most commonly used material of valve body, valve bonnet, and the wedge is A216 WCB, and after NACE MR-01-75 or NACE MR-01-03 treatment, A216 WCB material is also often used in the condition of slight corrosion. One thing to note, however, is that the temperature range of A216 WCB is -29℃ to 425℃.

Gate Valve Parts

  • The valve body is the primary part of the valve which holds everything together. Mostly it is connected to piping through flange and gasket. It is the pressure boundary of the valve.
  • The valve bonnet is the second boundary of pressure. It is connected with a valve body with bolts or flange.
  • The valve trim collectively stems, seat, and the disk is known as valve trim. Valve performance is dependent on seat and disk arrangement.
  • The seat and disk are the most important part of the gate valve. It contains a gate-type disk and seat which fits the disk tightly.
  • The stem connects the actuator and disk in the gate valve. It opens and closes the disk and seat arrangement. Two types of the stem are available one is rising which rises when we open the valve and the other is non-rising which has no vertical motion.
  • Valve Actuator is a manual wheel which operates stem and disk arrangement.

How to Select Valve Materials

The challenge in making a material choice is actually verifying that the chosen material best fits the application. This involves taking into account working conditions and flow media properties.

Most important concerning the working conditions is to know the pressure and temperature ratings and for working media is to take in consideration corrosive and erosive properties. Additionally, it might be needed to consider thermal and physical shock, line stress and fire hazards.

Broadly speaking when considering temperature limitations of different groups of materials Table 1. should be used as general reference for material selection.

Range Temperature(°F) Material
Very High 2000 Refractory Metals, Ceramics
High 1600 High Temperature
1200 Alloy Steels
Intermediate 1000 Carbon Steel
650 Ductile Iron
550 Bronze
450 Cast Iron
150 PVC Plastic
Low -250 Low Alloy Steels
Bronze
Very Low(Cryogenic) -450 Bronze, Austenitic Ductile Iron
Austenitic Stainless Steels

In some cases a compromise must be reached in selecting a material. Some service conditions require use of exotic alloys and metals to withstand particular corrosive properties of the flowing fluid. These materials are much more expensive than common metals, so economy may also be a factor in material selection. Table 2 shows ASTM materials widely used for valve bodies and bonnets.

ANSI Class Material ASTM Specification
125 Bronze B 62
125 Cast Iron A216 Cl. B
150 Bronze B 62 / B 148
150 Carbon Steel A216 GR. WCB
150 Forged Steel A105
150 Ductile Iron A536
200 Bronze B 61 / B 148
250 Cast Iron A216 Cl. B
300 Carbon Steel A216 GR. WCB
300 Forged Steel A105
600 Carbon Steel A216 GR. WCB
600 Forged Steel A105
Table 2

The trim typically includes a disk, seat, stem, and sleeves needed to guide the stem. Valve trim materials in relation to temperature limits should be selected in according to Table 3.

MATERIAL APPLICATION LOWER UPPER
°F °C °F °C
304 SST, S30400, CF8 Uncoated Plugs and Seats -450 -268 600 316
316 SST, S31600, CF8M Uncoated Plugs and Seats -450 -268 600 316
317 SST, S31700, CG8M Uncoated Plugs and Seats -450 -268 600 316
416 SST, S41600, 38 HRC min Cages, Plugs and Seats -20 -29 800 427
CA6NM, 32 HRC min Cages, Plugs and Seats -20 -29 900 482
Nitronic 50, S20910 High Strength Condition Shaft, Stem and Pins -325 -198 1100 593
440 SST, S44004 Bushings, Plugs and Seats -20 -29 800 427
17-4PH, S17400, CB7Cu-1, H1075 Condition Cages, Plugs and Seats -80 -62 800 427
Alloy 6, R3006, CoCr-A Plugs and Seats -325 -198 1500 816
Electroless Nickel Coating Trim Coating -325 -198 750 400
Hard Chromium Plating Trim Coating -325 -198 600 316
Hard Chromium Plating on V-Balls Trim Coating -325 -198 800 427
Hard Chromium Coating Trim Coating -325 -198 1100 593
Monel K500, N05500 Uncoated Plugs and Seats -325 -198 800 427
Monel K400, N04400 Uncoated Plugs and Seats -325 -198 800 427
Hastelloy B2, N10665, N7M Uncoated Plugs and Seats -325 -198 800 427
Hastelloy C276, N10276, CW2M Uncoated Plugs and Seats -325 -198 800 427
Titanium Grades 2, 3, 4, C2, C3, C4 Uncoated Plugs and Seats -75 -59 600 316
Nickel, N02200, CZ100 Uncoated Plugs and Seats -325 -198 600 316
Alloy 20, N08020, CN7M Uncoated Plugs and Seats -325 -198 600 316
NBR, Nitrile Rubber Seats -20 -29 200 93
FKM Fluoroelastomer Seats 0 -18 400 204
PTFE, Polytetrafluoroethylene Seats -450 -268 450 232
PA, Nylon Seats -60 -51 200 93
HDPE, High Density Polyethylene Seats -65 -54 185 85
CR, Chloroprene Seats -40 -40 180 82

Gate Valve for Sale List by Material

Material Choices of Gate Valve

Like high-temperature conditions, the medium is high-temperature steam or hot air conditions, usually, the choice of materials for high-temperature-resistant materials such as A217 WC6, A217 WC9, the temperature range of A217 WC6 & A217 WC9 is -29℃ to 593℃.

A352 LCB, A352 LCC is usually used for a low-temperature application, usually, the medium is of low-temperature but over -46℃ or through conduit gate valve is installed outdoor in area of a cold environment. But these materials can not be used for high-temperature over 345℃.

A351 CF8, A351 CF8M, A351 CF3, A351 CF3M, these austenitic stainless steel are anti-rust and anti-corrosion, suitable for the medium of various kinds of acid. A351 CF8, A351 CF8M, A351 CF3 & A351 CF3M can be used in most low temperature conditions, but it needs cryogenic treatment. It can also be used in most high-temperature conditions, but there are corresponding standards for carbon content.

Aluminum-bronze like B148 C95800, B62 C83600, B283 C61300, and other Al-bronze are perfectly suitable for seawater application.

Duplex Steel A890 4A, A890 5A, SAF2205, S31803 and super duplex steel A890 6A, SAF2507, S32750 have similar application range of Al-Bronze, they have good resistance to chloride corrosion, so they are widely used for seawater application and produced water application.