Cryogenicl Gate Valve

Size: 1/2" - 24" (DN15 - DN600)

Pressure: Class 150 - 600 / PN 10-100

Standard: API 6D, BS 6364, MSS SP-134, ASME B16.34

Body Materials: A351 CF8M (cast 316), A351 CF8 (cast 304), A216 WCB (cast carbon steel, -46°C min)

Seat: Metal-to-metal, flexible wedge or solid wedge gate

Design: Cast body, flanged or butt weld ends, extended bonnet, rising stem (OS&Y) or non-rising stem, body cavity vent

The Valve That Covers Everything

This is the baseline cryogenic gate valve. The one that shows up on every LNG plant spec sheet. The one that handles 1/2" through 24" in a single design. It's not specialized. It's not the forged-body premium version. It's not the compact two-piece option. It's the general-purpose isolation valve that works at every cryogenic temperature from -46°C down to -196°C.

And that breadth is its strength. When you're specifying valves for an entire cryogenic process line—LNG processing, air separation, ethylene cracking—you need one valve type that covers the range. You don't want three different gate valve designs for three different size ranges. You want one. This is that one.

Cast Body—Practical at Size

Let's talk about the cast body honestly. A351 CF8M at -196°C. A216 WCB at -46°C. Cast, not forged.

Forged bodies are better—no porosity, no hidden voids, no potential leak paths. We make forged versions. But at sizes above 12", forged bodies cost two to three times what cast bodies cost. The forging process at large diameters is expensive. Cast is cost-effective. And for most applications—not the critical isolation points, not the safety shutdowns, but the standard process isolation on a cryogenic line—cast A351 CF8M works. It holds. It seals. BS 6364 cryogenic testing confirms it.

You specify forged for the critical points. You specify cast for the rest. That's how real plants are built.

Flexible Wedge for Deep Cold, Solid Wedge for Moderate

At -196°C, the gate and body contract differently. Different sections cool at different rates. A solid wedge gate can bind. The flexible wedge—two discs with a center ball—adjusts independently against each seat ring. Seating stays tight. Opening stays manageable.

At moderate cryogenic temperatures—-46°C to -100°C—the contraction differential is smaller. A solid wedge gate seals fine. It's simpler. It's cheaper. It's more reliable because there's less mechanism to maintain. For air separation plant isolation at -100°C, solid wedge is the practical choice.

We offer both. You pick based on your operating temperature.

The Body Cavity Vent—Trapped Gas Kills Valves

Cryogenic gate valves have a vent hole on the body cavity. Here's why.

When the valve closes, liquid cryogenic media fills the body cavity around the gate. As the surrounding temperature fluctuates, that liquid can evaporate. Gas pressure builds inside the cavity. The gate gets locked—pressure on both sides of the wedge, no way to open it without equalizing first.

The vent hole lets that gas escape. Pressure equalizes. The gate moves freely. It's a small detail. But without it, the valve fails in service—not because the materials are wrong, not because the design is bad, but because trapped gas pressure locks the mechanism.

BS 6364 requires it. We put it on every valve we build.

Extended Bonnet—Same Principle, Any Size

The packing gland needs to stay warm. At -196°C, packing freezes. The stem seizes. You can't operate the valve. The extended bonnet lifts the packing away from the cold zone—30°C ambient at the gland, -196°C at the body. Every cryogenic valve needs this. This one has it. From 1/2" to 24". Same principle. Same reliability.

A: At sizes above 12", forged bodies cost 2-3x more than cast. For standard process isolation—not critical safety shutdowns—cast A351 CF8M is cost-effective and performs reliably. BS 6364 cryogenic testing validates cast body performance. You reserve forged bodies for the critical points and use cast for the rest.

A: Flexible wedge for deep cryogenic service at -196°C where differential thermal contraction can bind a solid gate. Solid wedge for moderate cryogenic temperatures (-46°C to -100°C) where contraction differential is small enough that a solid wedge seals reliably without the flexibility mechanism.

A: When the valve closes, liquid in the body cavity can evaporate and build gas pressure, locking the gate between two pressure forces. The vent hole lets gas escape so the gate can move freely. BS 6364 requires this feature on all cryogenic gate valves.

A: Class 150 through Class 600 (PN 10-100). The cast body and metal-to-metal seat design handle the full range. At higher pressures, consider the forged steel version for zero-porosity body integrity.

A: Rising stem (OS&Y) gives visible position indication—you can see if the valve is open or closed by looking at the stem. Critical for isolation verification before maintenance or hot work. Non-rising stem saves vertical space in tight installations but requires a separate position indicator.