Low-Temperature Steel Gate Valve DN150 Price & Selection: For -46°C Service
In LNG, ethylene, air separation, and refrigeration systems, gate valves must withstand -46°C or lower. Standard carbon steel (e.g., WCB) becomes brittle below -29°C, so low-temperature steel (LCB/LCC) is mandatory. This article covers 2026 price and key selection parameters for DN150 (6″) valves rated for -46°C.The main gate valves product names of China gate Valve Network include:Electro-hydraulic Wafer Knife-shaped Gate Valve,Electric Slurry ValveElectric Flange Gate Valve,Fire Special Signal Relisient Seat Seal Gate Valve,Fire Special Rising Stem Resilient Seat Seal Gate Valve,Forged Steel Socket Welding Valve,Forged Steel Flange Gate Valve,
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2026 Price Reference (USD, ex-works)
| Material | Pressure | Connection | Seat Type | Unit Price (USD) |
|---|---|---|---|---|
| LCB (-46°C) | PN16 | Flanged | Metal hardfaced (13Cr/Stellite) | 440–625 |
| LCB | Class 150 | Flanged (ANSI) | Metal seated | 500–695 |
| LCC (-46°C) | PN25 | Flanged | Metal hardfaced | 585–805 |
| LCC | Class 300 | Flanged (ANSI) | Metal seated | 765–1040 |
Price drivers: LCC costs 15–25% more than LCB. Stellite hardfacing adds 15%. Extended bonnet (for cold box) adds 30–50%. Low‑temperature impact test report adds 10%.
Key Selection Parameters
1. Material
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LCB (ASTM A352 Grade LCB): service down to -46°C, typical for LNG and ethylene.
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LCC: stronger, suitable for -46°C to -60°C, higher pressure ratings.
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Stem & fasteners: must be 304 or 316 stainless steel (austenitic, no low‑temperature embrittlement). Never use carbon steel.
2. Design features
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Extended bonnet: prevents stem seal freezing, ensures stable operating torque. Mandatory for cold box valves.
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Drip pan: stops condensate from dripping onto insulation.
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Rising stem: preferred for visual position indication; stem threads stay away from cold media.
3. Seating surface
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13Cr stainless steel or Stellite hardfacing – hard, gall‑resistant. Do not use copper alloy or PTFE (they become brittle at low temperature).
4. Pressure & testing
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Shell hydrostatic test = 1.5× rated pressure.
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Seat tightness tested at room temperature and verified by low‑temperature impact testing of materials.
5. Connection standard
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GB/T 9113 or HG/T 20592 – preferred flange facing: MFM (male & female) or TG (tongue & groove).
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ANSI B16.5 for Class ratings.
Installation & Maintenance Tips
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Pre‑cooling: purge with dry nitrogen to remove moisture, then slowly introduce cold media to avoid thermal shock.
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Insulation: apply cold insulation on body and below the extended bonnet, but never cover stem packing or handwheel.
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Gasket: use spiral‑wound stainless steel with graphite filler or pure PTFE. No asbestos.
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Bolting: 304 or 316 stainless steel bolts with anti‑seize lubricant.
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Operation: stem packing resistance increases at low temperature – operate slowly and gently. Never use a cheater bar.
Common Low‑Temperature Problems & Solutions
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External leakage: packing contracts at low temperature. Tighten gland nuts evenly; if persists, replace with cryogenic‑rated packing (PTFE or flexible graphite).
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Internal leakage: often due to ice or debris on seat. Cycle valve a few times, then blow with warm nitrogen to thaw.
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Stem sticking: moisture freezing in threads. Use extended bonnet and, for severe cases, electric heat tracing.
Alternative Comparison
| Valve Type | Pros | Cons | Suitability |
|---|---|---|---|
| Low‑temp steel gate (LCB/LCC) | Moderate cost, reliable to -46°C | Heavier than stainless | LNG branches, ethylene tanks |
| SS304/316 gate valve | Works to -196°C, corrosion resistant | 2–3× cost | Below -100°C or corrosive cryogenic |
| Cryogenic ball valve | Fast operation, good seal | Higher cost, higher flow resistance | Frequent cycling |
