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

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.