Parallel Gate Valve F91 Open Die Forged—14″ 1500LB RTJ

Description

14″ – Class 1500

Open Die Forged F91 · Pressure Self-Sealing · Parallel Gate Valve
TECHNICAL DATA SHEET

1. General Description

This valve is a 14-inch, Class 1500, pressure seal bonnet, parallel disc gate valve. The body is manufactured from ASTM A182 F91 material using the open-die forging process. It is specifically designed for severe high-temperature, high-pressure service conditions (e.g., ultra-supercritical thermal power plants, high-temperature steam piping, etc.). The parallel twin-disc design ensures reliable sealing even under large temperature and pressure fluctuations, with low operating torque and no risk of wedging.

2. Applicable Standards & Codes

Item Standard / Code
Design & Manufacture ASME B16.34, API 600
Pressure-Temperature Ratings ASME B16.34 (Material Group for F91)
Face-to-Face Dimensions ASME B16.10 (Long Pattern)
Butt-Weld Ends ASME B16.25
Inspection & Testing API 598, API 600
Pressure Seal Bonnet Design Manufacturer’s standard, meeting ASME B16.34 pressure boundary requirements
Materials ASTM A182 F91 (Open Die Forged), ASME BPVC Section II & relevant standards
3. Main Technical Parameters

Parameter Description
Nominal Size 14 inch (DN 350)
Pressure Class Class 1500 (ASME B16.34)
Body Material ASTM A182 F91 (Open Die Forged)
End Connection Butt-Weld (BW) per ASME B16.25, bevel for SCH 160 / XXS pipe wall
Bonnet Type Pressure Seal (Self-Sealing)
Disc Type Parallel twin disc, spring-energized, self-sealing
Operation Handwheel / Bevel gear operator (standard); Electric or Pneumatic actuator (optional)
Flow Direction Bi-directional sealing, no flow restriction
Service Media Steam, boiler feed water, high-temperature oil, other high-temperature non-corrosive fluids
Operating Temperature Range -29 °C to 620 °C (based on ASME B16.34 F91 pressure-temperature ratings)
Hydrostatic Test Pressure (ambient temp.) Shell: 38.9 MPa.g (5630 psig); Seat: 28.3 MPa.g (4100 psig)
Leakage Class Zero leakage (metal-seated with Stellite hardfacing, meets API 598)
4. Typical Bill of Materials

No. Part Name Material Remarks
1 Body ASTM A182 F91 Open Die Forged, Normalized & Tempered
2 Bonnet ASTM A182 F91 Open Die Forged, Normalized & Tempered
3 Disc (Gate) ASTM A182 F91 Seating faces hardfaced with Stellite Gr.6 / HF
4 Seat Ring ASTM A182 F91 Renewable seats, seating face Stellite Gr.6 overlay
5 Stem ASTM A479 Gr.91 / ASTM A182 F91 Nitrided or chrome-plated surface hardening, precision ground
6 Pressure Seal Ring High-purity graphite + Stainless steel reinforced Self-sealing, rated to 650 °C
7 Bonnet Retainer Ring (Segmental Ring) ASTM A182 F91 / High-strength alloy steel Machined from bar/forging
8 Packing High-purity flexible graphite braided With corrosion inhibitor, die-formed rings
9 Gland & Gland Flange ASTM A182 F91 Spherically faced, self-aligning
10 Yoke / Bracket ASTM A216 WCB or A182 F91 Rigid design, for rising stem assembly
11 Stem Nut Copper Alloy (ASTM B148 C95400) / Steel base self-lubricated With grease fitting
12 Disc Spreader Spring Inconel X-750 For parallel disc forced extension
13 Fasteners ASTM A193 B16 / A194 Gr.4 Fully high-temperature alloy
5. Approximate Dimensions & Weight

The dimensions below are based on standard design. Final confirmed drawing shall prevail.

Specification Unit Value
Nominal Size inch (mm) 14 (DN350)
Face-to-Face, BW (L) mm 1397
Max. Body Outer Diameter mm Approx. 920
Height from Stem Center to Top (Open) mm Approx. 2650
Handwheel Diameter mm Approx. 900
Stem Diameter mm Approx. 63
BW End OD / Wall Match – Match pipe 355.6 mm OD × SCH 160 / XXS
Approx. Total Weight kg Approx. 3,800 (Manual Bevel Gear)
Note: Height and weight include bevel gear operator. Electric actuation will significantly increase both height and weight.

6. Design & Manufacturing Features

Open Die Forged Body: Complete grain flow and dense microstructure dramatically enhance creep rupture strength and fatigue resistance under high-temperature internal pressure; eliminates casting defect risks.
F91 Modified 9Cr-1Mo-V Steel: Excellent elevated temperature strength, permitting service up to 620 °C; superior long-term creep strength compared to traditional F11/F22; low thermal expansion coefficient.
Pressure Seal Bonnet: The higher the system pressure, the tighter the bonnet seal. The pressure seal ring uses pure graphite composite gasket to achieve leaktight performance and easy maintenance.
Parallel Twin-Disc Design: Two discs are forced apart by internal springs, maintaining intimate contact with the seats for bi-directional zero leakage. Eliminates the thermal seizure risk of wedge gates, requiring extremely low opening/closing torque and enabling smaller actuators.
Fully Guided Discs: Disc carrier accurately engages body guide ribs, ensuring smooth disc alignment into seats at any valve position, extending seat life.
Renewable Seat Rings: Seats are fixed in the body by threads or welding + seal welding; seating faces are hardfaced with Stellite. Field replaceable, considerably extending body service life.
Blow-out Proof Stem: Stem shoulder and bonnet incorporate anti-blowout feature in compliance with API 600, ensuring safety under high pressure.
Long-Life Packing System: Deep stuffing box with flexible graphite rings and braided anti-extrusion end rings; self-lubricating, low friction. Uniform compression achieved via spherical gland flange, suitable for frequent operation.
7. Pressure-Temperature Ratings Reference

(ASME B16.34, Material F91, Class 1500)

Service Temperature (°C) Max. Allowable Working Pressure (MPa.g)
-29 ~ 38 25.8
100 25.8
200 24.8
300 23.1
400 21.6
500 19.8
550 16.2
600 10.9
620 9.0
Note: Values are for reference only. Exact ratings shall be per ASME B16.34 latest edition. Material in normalized & tempered condition, without improper heat treatment.

8. Inspection, Testing & Documentation

All valves are 100% hydrostatically tested per API 598, including shell strength, high-pressure seat test (metal seated) and low-pressure air seat test (optional).
Body and bonnet forgings are normalized and tempered per ASTM A182 requirements; chemical composition and mechanical property reports are provided.
Available as option: 100% Ultrasonic Examination (UT), Liquid Penetrant Examination (PT) on critical surfaces, Radiographic Examination (RT) of welds (e.g., seat ring seal weld confirmation).
Standard Documentation Package: Material test certificates, hydrostatic test reports, certificate of conformance, and installation & maintenance manual. EN 10204 Type 3.1 or 3.2 certificates available upon request.
Valves are cleaned, degreased, and end-protected, suitable for transport and installation.
9. Typical Applications

Main steam & hot reheat isolation valves in Ultra-Supercritical (USC) thermal power plants
High-temperature reheat systems in gas-steam combined cycle power plants
High-temperature hydrogenation, reforming, and other process units in refineries & petrochemical plants
High-temperature steam systems in the conventional island of nuclear power plants
Molten salt/steam line isolation in Concentrated Solar Power (CSP) plants
10. Additional Selection Notes

Operation: Standard is bevel gear manual. For electric, pneumatic, or hydraulic actuators, please specify power/signal parameters, required stroking time, and torque safety margin.
Bypass System: For large-diameter Class 1500 high-temperature gate valves, a bypass valve is recommended to equalize pressure and reduce operating force. It can be integrally mounted on the valve body or externally piped.
Purge/Drain Connections: Can be added at the bottom of the body upon request.
Mating Pipe Specification: Confirm butt-weld end preparation at time of order.
This technical data sheet is based on standard design. Minor variations may occur due to manufacturing optimization. Final dimensions and parameters are subject to the manufacturer’s certified documentation.