AHN42F Parallel Safety Back-Flow Relief Valve
Specialized spring-loaded parallel safety back-flow valve designed for liquid phase discharge systems, LPG pumping stations, and cryogenic vapor return loops. Automatically relieves overpressure back into storage tanks to safeguard pump impellers and pipeline headers.
Design Criteria & Manufacturing Specifications
Manufactured strictly to international safety relief valve codes with 100% factory set pressure testing, cryogenic/high-temperature seal verification, and full EN 10204 3.1 material traceability.
| Engineering Parameter | Applicable Codes, Standards & Design Criteria |
|---|---|
| Design & Sizing Standard | API 526, API 520 Part I & II, ASME Section VIII Div 1, GB/T 12243 |
| Face-to-Face Dimension | Manufacturer Standard / ASME B16.10 Specialized Flanged Geometry |
| Flange Drilling & Facing | ASME B16.5 Class 150 / 300 / 600 RF; EN 1092-1 Form B1 / B2 |
| Pressure Class Range | PN 1.6 to 6.4 MPa (ASME Class 150 to Class 600) |
| Nominal Diameter | DN 25 to DN 100 (NPS 1" to 4") Full Bore & Standard Bore |
| Body Metallurgy | ASTM A216 WCB / A352 LCC (Low Temp) / A351 CF8M (Stainless Steel) |
| Trim, Disc & Spring | ASTM A276 316 + Stellite No.6 Overlay; 50CrVA / Inconel X-750 Spring with PTFE Resilient Insert |
| Testing & Inspection | API 527 Seat Tightness (Bubble-Tight), API 598 Shell Hydrostatic, TSG ZF001 Set Pressure Calibration |
AHN42F Parallel Back-Flow Safety Valve Standard & Engineered Models
Browse TSV's specialized lineup of AHN42F parallel back-flow safety relief valves engineered for LPG pumping stations, liquefied hydrocarbon storage tanks, and pump bypass loops. Each valve is 100% calibrated on our digital test bench.
AHN42F-25C Standard Flanged LPG Pump Bypass Back-Flow Relief Valve
Heavy-duty carbon steel spring-loaded bypass valve engineered for LPG pump discharge loops, featuring dual parallel chambers and resilient soft-seat insert for zero bubble leakage.
AHN42F-40P Stainless Steel Ammonia & Corrosive Media Back-Flow Valve
Complete ASTM A351 CF8M austenitic stainless steel construction with bellows seal isolation, preventing aggressive liquid chemical fumes from attacking internal spring components.
AHN42F Low-Temperature Tank Truck & Terminal Back-Flow Return Valve
Impact-tested low temperature alloy body design engineered for road tanker loading racks and storage vessel vapor equalization headers, ensuring reliable reseating down to -46°C.
AHN42F Dynamic Backpressure & Recirculation Sealing Principles
Engineered specifically for pressurized liquefied gas pump circuits, AHN42F parallel back-flow valves eliminate pump cavitational overheating and piping hydraulic slam through automated modulating liquid relief.
Dynamic Differential Relieving
Modulates liquid recirculation volume in direct proportion to upstream pump discharge pressure. When piping resistance drops, the valve smoothly returns to bubble-tight closure without pressure spikes.
Zero-Leakage Resilient Disc Insert
Combines a primary fluoropolymer resilient elastomeric boundary with precision-lapped metal-to-metal secondary backup, ensuring API 527 zero bubble leakage under volatile liquefied gas conditions.
100% Set Pressure Bench Calibration
Every AHN42F assembly is individually tested and calibrated on TSV high-precision safety valve test rigs with digital pressure recording and full EN 10204 3.1 inspection certification before packing.
Explore All 4 Safety & Relief Valve Sub-Categories
1:1 aligned with TSV factory catalog. Navigate to spring full-lift steam safety, modulating pilot-operated, parallelled back-flow, or thermal relief valves.
Spring Safety Valve
ASME I & VIII full-lift enclosed spring safety valve with blowdown control rings for boilers and vessels.
ASME I & VIII Full Lift View Details →Pilot-Operated Safety Valve
Modulating and snap-action pilot valves operating bubble-tight up to 98% of set pressure on gas pipelines.
API 526 Pilot Operated View Details →Parallelled Safety Valve
Specialized parallel dual-chamber safety back-flow valve for liquid discharge, LPG pump bypass, and vessel return.
Current Series View Page Top ↑Thermal Relief Valve
Compact high-pressure thermal expansion relief valves protecting piping, heat exchangers, and liquid lines.
API 526 / ASME VIII View Details →Configure & Request a Quote for AHN42F Parallel Safety Valves
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