NPS 4″ Class 1500 RTJ API High Pressure Globe Valve – CF8M – Pressure Seal Bonnet (PSB)
NPS 4″ (DN100) Class 1500 (PN250) Ring Type Joint Flanged (RTJ) API High Pressure Globe Valve (CF8M Body, Pressure Seal Bonnet (PSB), Handwheel). Manufactured to ASME B16.34 and BS 1873 / API 623 with API Trim 5 (Full Stellite 6 Hardfacing on Conical Plug & Seat). Engineered for precise severe-service throttling, anti-cavitation erosion defense, blowout-proof rising stem (OS&Y), and ISO 15848-1 Class AH low-emission live-loaded flexible graphite packing.
Description
The NPS 4″ (DN100) Class 1500 (PN250) Ring Type Joint Flanged (RTJ) API High Pressure Globe Valve (CF8M) is an engineered severe-service linear flow regulation and shutoff valve manufactured by XIAMEN GUTE VALVE MANUFACTURING COMPANY. Designed in strict compliance with ASME B16.34, BS 1873, and API 623, it is built for extreme-pressure, high-temperature industrial pipelines where precise throttling, anti-cavitation durability, and zero pressure boundary leakage are mandatory. Featuring an engineered Pressure Seal Bonnet (PSB), API Trim 5 full Stellite 6 hardfacing on the conical plug disc and seat, an Outside Screw & Yoke (OS&Y) rising stem, and live-loaded low-emission flexible graphite packing, it guarantees dependable process control across supercritical boiler feedwater, steam turbine bypass, high-pressure blowdown, and refinery hydrocracking units.
Engineering Configuration & Dimensional Specifications
NPS 4″ (DN100) | Class 1500 (PN250) | CF8M Body | Ring Type Joint Flanged (RTJ) | PSB | ASME B16.34 / BS 1873 / API 623
- Face-to-Face / End-to-End Dimension (L): 549 mm (ASME B16.10 Table 1 / Table 2)
- Center-to-Handwheel Fully Open Height (H): ~870 mm
- Bare Valve Assembly Net Weight: ~310 kg
- Bonnet Sealing Technology: Pressure Seal Bonnet (PSB)
- Trim Metallurgy & Disc Geometry: Trim 5 (Stellite) – Conical Plug (PTA Stellite 6 Overlay, Hardness 38–42 HRC)
- Stem & Actuation Interface: OS&Y Rising Stem, ACME Thread, Handwheel
Core Structural Engineering: Linear Throttling & High-Pressure Containment
Severe-service globe valves require specialized hydrodynamic internal flow contours to handle extreme kinetic energy dissipation without acoustic resonance, cavitation damage, or bonnet joint failure.
- Pressure Seal Bonnet (PSB): Pressure Seal Bonnet (PSB) utilizing an internal self-energizing metallic segment ring and a soft iron or silver-plated 316 stainless steel pressure seal gasket. Internal pipeline pressure exerts an upward hydraulic thrust against the bonnet plug, driving it into the wedge-shaped gasket. As system pressure escalates, joint tightness multiplies automatically, eliminating bulky body-bonnet flanges and preventing external leakage during thermal cycling.
- Conical Plug Disc Geometry: Specifically contoured for high differential pressure throttling, providing precise linear flow characteristics, high rangeability, and positive metal-to-metal seating contact.
- Flow Direction Dynamics: Flow under the disc (bottom-to-top, FUD) is standard per BS 1873, which isolates the stem packing chamber from continuous line pressure when the valve is closed, prolonging packing life and reducing opening torque. For high differential pressure steam applications, optional balanced trim or flow-over-the-disc (FOD) with downstream bypass can be engineered upon request.
Rigorous Quality Assurance & API 598 Pressure Testing Protocols
- 1. Material Traceability & PMI: 100% Positive Material Identification (PMI) spectroscopic analysis on all pressure-retaining casting and forging heats with certified EN 10204 3.1 Mill Test Reports (MTR).
- 2. High-Pressure Hydrostatic Shell Test: Every individual valve undergoes hydrostatic shell testing at 1.5x Cold Working Pressure (CWP) per API 598 with zero allowable leakage.
- 3. Hydrostatic & Air Seat Closure Test: 100% verified for bubble-tight shutoff under high-pressure liquid closure (1.1x CWP) and low-pressure air seat test (6 bar).
- 4. Non-Destructive Examination (NDE): 100% Magnetic Particle (MT) or Dye Penetrant (PT) examination on Stellite overlays; 100% Radiographic (RT) or Ultrasonic (UT) testing on critical high-stress casting sections per ASME B16.34.
Frequently Asked Technical Questions
A: Conventional bolted bonnets rely solely on bolt torque to compress the gasket. Under Class 1500 pressures (up to 103.4 MPa) and extreme thermal gradients, bolt creep and relaxation inevitably cause joint weeping. Gute Pressure Seal Bonnets position the metallic gasket inside an inverted body taper. Internal line fluid drives the bonnet plug upward against the silver-plated gasket and segmental retention ring. The higher the line pressure, the tighter the wedge seal becomes, completely eliminating joint leakage and reducing overall valve weight by 35–45%.
A: In small-to-medium bore NPS 4″ (DN100) lines operating under extreme differential pressure, fluid accelerates to near-sonic velocities across the seat. Gute conical plug discs feature Plasma Transferred Arc (PTA) Stellite 6 overlays (38–42 HRC) across both seating faces. The narrow tapered conical seat provides linear flow regulation, breaks through particulate scale, and maintains narrow contact line seating that neutralizes wire-drawing erosion and seat galling during sustained micro-throttling.
A: The standard flow configuration is ‘flow under the disc’ (bottom-to-top). When the valve is closed, high line pressure acts against the bottom of the disc, leaving the bonnet neck and stem packing chamber isolated from continuous high pressure and temperature. This significantly extends packing service life, reduces fugitive emissions (ISO 15848-1 Class AH < 100 ppmv), and allows the integral backseat to be engaged safely during emergency repacking.
Need Project-Specific High Pressure Globe Valve Sizing or Actuation Packages?
Contact Gute Valve technical engineering team for certified dimensional drawings, flow coefficient (Cv) curves, multi-turn electric actuator sizing (Rotork, AUMA), or high-temperature NDE documentation.
Additional information
| Material | |
|---|---|
| Pressure | |
| Valve Size | |
| Connection | |
| Design Standard | ASME Standard |
| Size | NPS 4″ |
| Pressure Class | Class 1500 |
| Body Material | CF8M |
| End Connection | RTJ |
| Operation | Handwheel |
| Design Structure | Pressure Seal Bonnet (PSB) |
| Manufacturer | XIAMEN GUTE VALVE MANUFACTURING COMPANY |
| Trim / Disc Type | Trim 5 (Stellite) – Conical Plug |
