14"-1500LB Open Die Forged F91 Pressure Self-Sealing Parallel Gate Valve

Description

Technical Data Sheet

Pressure Self-Sealing Parallel Gate Valve
(Free Forging Process, Flanged Ends)

1. General Description

Product Type: Parallel Gate Valve (Parallel Disc / Parallel Slide Gate Valve)
Body Construction: Free Forging Process – Solid forged body for enhanced strength and grain structure
Bonnet Design: Pressure Self-Sealing (Pressure Seal) Bonnet – Utilizes line media pressure to enhance sealing
Disc Type: Parallel double disc / Parallel slide design
End Connections: Flanged (ASME / EN / GB standards)
Operation: Handwheel / Gearbox / Electric / Pneumatic actuator
Design Standard: API 600 / API 6D / ASME B16.34 / GB/T 12234
Face-to-Face: ASME B16.10 / API 6D / GB/T 12221
Test Standard: API 598 / API 6D / GB/T 13927
Temperature Range: -196°C to +600°C (depending on materials)
Pressure Rating: Class 150 – Class 2500 / PN16 – PN420

2. Application

Suitable Media: High-pressure steam, high-temperature fluids, oil & gas, corrosive media, cryogenic services, water
Typical Industries: Power generation (thermal/nuclear), petrochemical, oil & gas refineries, pipelines, metallurgy, marine, and high-pressure industrial systems
Special Features: Suitable for high-temperature, high-pressure, and severe service conditions

3. Technical Parameters

Parameter	Specification Range
Nominal Diameter (DN)	DN10 – DN600 (2″ – 24″)
Pressure Rating	Class 150 – Class 2500 / PN16 – PN420
Shell Test Pressure	1.5 x rated pressure (per API 598)
Seat Test Pressure	1.1 x rated pressure (per API 598)
Leakage Rate	API 598 / ISO 5208 Rate D (metal seated) – Zero leakage optional with soft seal inserts
Operating Temperature	-196°C to +600°C
Flow Direction	Bi-directional
Bonnet Type	Pressure Self-Sealing (Pressure Seal) – Seal efficiency increases with pressure

4. Materials of Construction

Component	Material Options	Notes
Body	Forged Steel (A105 / F11 / F22 / F304 / F316 / F51)	Free forging process – superior grain structure, no porosity
Bonnet	Forged Steel (same as body)	Pressure self-sealing design
Disc / Gate	Forged Steel + Hardfacing (Stellite)	Parallel double disc design; hardfaced seat faces for wear resistance
Seat Rings	Stainless Steel / Inconel + Stellite hardfacing	Integral or welded-in design
Stem	Stainless Steel (304/316/17-4PH) / Inconel	Rolled threads for strength; anti-blowout design
Stem Nut	Aluminum Bronze / Ni-Resist	High strength, low friction
Pressure Seal Ring	Flexible Graphite + Stainless Steel wire reinforcement	Seals between bonnet and body; pressure energized
Gland Packing	Flexible Graphite / PTFE	High-temperature, low-friction
Bonnet Gasket	Spiral Wound (SS + Graphite) / Metal Jacketed	For pressure seal bonnet, main seal is pressure seal ring
Bolting	Alloy Steel (ASTM A193 B7 / B16)	High-strength studs and nuts
Yoke / Operator Mount	Carbon Steel / Fabricated Steel	ISO 5211 mounting pad for actuator
Coating	High-temperature resistant paint / Epoxy	As specified

5. Pressure Self-Sealing Bonnet Design – Working Principle

The pressure self-sealing bonnet (压力自密封阀盖) is a critical feature of this valve, offering significant advantages in high-pressure applications .

Feature	Benefit
Pressure-Energized Seal	Line media pressure pushes the bonnet upward, compressing the seal ring against the body taper. Higher pressure creates tighter seal
Simplified Design	Eliminates large flange connections and heavy bolting required for conventional bonnets
Compact & Lightweight	Reduces valve weight and overall height compared to bolted bonnet designs
Reliable at High Pressure	Ideal for high-pressure steam and critical services where bolted connections may relax under thermal cycling
Seal Ring Materials	Flexible graphite with SS reinforcement provides excellent resilience and temperature resistance
Preload Mechanism	Initial seal is achieved by pre-tensioned bolts/studs; pressure maintains seal thereafter

The self-sealing principle: A seal ring (typically flexible graphite reinforced with stainless steel wire) is positioned between the bonnet and the body. The bonnet has a tapered surface. Internal pressure acts on the bonnet, forcing it upward and compressing the seal ring against the mating taper in the body. This creates a pressure-energized seal – the higher the pressure, the tighter the seal .

6. Free Forging Process – Advantages

The use of free forging (自由锻造) for the valve body provides superior mechanical properties compared to cast or rolled constructions:

Advantage	Benefit
Enhanced Grain Structure	Forging aligns grain flow with part contours, increasing strength and fatigue resistance
No Porosity / Voids	Eliminates casting defects such as porosity, slag inclusions, and shrinkage
Superior Mechanical Properties	Higher tensile and yield strength compared to cast equivalents
Excellent Impact Resistance	Suitable for high-pressure, thermal cycling, and severe service conditions
Material Traceability	Fully traceable mill certificates available per EN 10204 3.1/3.2

7. Parallel Gate Design – Features

The parallel disc / parallel slide gate design offers specific advantages over wedge gate valves :

Feature	Benefit
Parallel Discs	Two parallel discs expand against seats when closing, providing tight shut-off
Low Torque Operation	Minimal friction during opening/closing – only stem packing friction
No Jamming	Parallel design prevents thermal binding – discs remain free even at high temperatures
Self-Aligning	Disc assembly self-aligns to seats, compensating for minor misalignment
Erosion Resistance	Flow path designed to minimize seat erosion during opening
Bi-directional Sealing	Seals effectively in both flow directions

8. Dimensions & Weights (Reference Values – Class 1500)

*Note: Dimensions vary by manufacturer and pressure class. Request certified drawing from manufacturer for exact dimensions. *

Size (inches)	DN (mm)	L (Face-to-Face) mm – RF	L (Face-to-Face) mm – RTJ	H (Open approx.) mm	Weight approx. (kg)
2″	50	368	368	550	45
3″	80	381	384	650	75
4″	100	457	460	750	110
6″	150	610	613	950	220
8″	200	737	740	1150	350
10″	250	838	841	1350	500
12″	300	965	968	1550	700
14″	350	1029	1038	1750	900
16″	400	1130	1140	1950	1200
18″	450	1219	1232	2150	1500
20″	500	1321	1334	2400	1900
24″	600	1543	1562	2800	2700

*(Note: Face-to-face dimensions based on ASME B16.10 for Class 1500. Higher pressure classes have longer face-to-face dimensions.)*

9. Testing (Per API 598 / API 6D)

Test	Test Pressure	Acceptance Criteria
Shell Hydrostatic Test	1.5 x rated pressure	No visible leakage through pressure boundary
Seat Leakage Test (High Pressure)	1.1 x rated pressure	Allowable leakage per API 598 for metal-seated valves (Rate D)
Seat Leakage Test (Low Pressure)	80 PSI (5.5 bar)	Visual inspection for leakage
Backseat Test	Rated pressure	No visible leakage when valve fully open

10. Options & Accessories

Operation: Handwheel, Bevel Gearbox, Electric Actuator, Pneumatic Actuator, Hydraulic Actuator
Stem Extension: For buried or insulated installations
Position Indicators: Mechanical flag, limit switches, positioners
Seal Materials: Flexible graphite, PTFE, semi-metallic
Hardfacing: Stellite (various grades) / Colmonoy / Tungsten Carbide
Special Designs: Cryogenic service (-196°C), Oxygen service, NACE sour service
Certification: Material certificates EN 10204 3.1/3.2, NACE MR0175, PED, ATEX

11. Ordering Information

To ensure correct selection, please specify:

Item	Specification
Valve Type	Pressure Self-Sealing Parallel Gate Valve – Forged Body
Size	______ inches / DN ______
Pressure Class	Class ______ / PN ______
Body Material	Forged ______ (e.g., A105, F22, F316)
Trim Material	______ (e.g., 13Cr, 304, 316 + Stellite)
Ends	Flanged – ASME B16.5 / EN 1092-1 / Other
Face-to-Face	ASME B16.10 / API 6D / Other
Operation	Handwheel / Gearbox / Actuator
Media / Temperature	______ / ______ °C
Special Requirements	NACE, Cryogenic, Oxygen cleaning, etc.

This data sheet is a guideline based on standard industry practice for Pressure Self-Sealing Parallel Gate Valves manufactured by free forging process . Always refer to the manufacturer’s certified drawings for exact dimensions and ratings

14″-1500LB Open Die Forged F91 Pressure Self-Sealing Parallel Gate Valve