Zeron Fastners
Industrial Valves & FastenersPressure Sealed Gate Valves
Pressure Sealed Bonnet Gate Valves are high-integrity isolation valves engineered specifically for severe high-pressure, high-temperature power plant steam headers, boiler feedwater systems, and chemical synthesis loops. Unlike conventional bolted bonnets where internal pipeline pressure tends to separate body-bonnet flanges, a pressure-seal valve utilizes internal system pressure to force the bonnet upward against an angled metal or graphite seal ring, creating an increasingly tighter seal as line pressure rises.
Zeron Fastners manufactures API 600 and ASME B16.34 Pressure Sealed Gate Valves in Class 900#, Class 1500#, Class 2500#, and Class 4500# in Chrome-Moly Alloy Steels (ASTM A217 WC6, WC9, C12A) and Cast Carbon Steel (WCB). Designed with flexible parallel slide or solid wedge gates, Stellite hardfaced seats, and precision live-loaded gland packing. Butt-weld end connections eliminate heavy flanges, dramatically reducing overall pipeline weight and thermal stress.
Technical Specifications
| Specification Feature | Details & Standard Compliance |
|---|---|
| Design Standards | ASME B16.34, API 600, BS EN 12266, IBR (Indian Boiler Regulations) |
| Size Range | 2" to 24" (DN50 - DN600) |
| Pressure Ratings | Class 900#, Class 1500#, Class 2500#, Class 4500# (PN150 to PN760) |
| Bonnet Style | Internal Pressure Seal Bonnet with Flexible Graphite or Silver-Plated Metallic Seal Ring |
| End Connections | Butt Weld (BW ASME B16.25) to suit Schedule 80, 160, XXS pipe |
| Body Materials | ASTM A216 WCB, A217 WC6, WC9, C12A (P91), A351 CF8M |
| Wedge / Disc | Flexible Wedge or Parallel Slide Discs with Stellite Gr. 6 Overlay |
| Seat Construction | Seal-Welded Heavy Stellite Overlay Body Seats |
| Stem Operation | Live-Loaded Gland Packing, Rising Stem with Heavy-Duty Enclosed Spur Gear or Bevel Gear |
| High Temperature Limit | Up to +600°C (+1112°F) Supercritical Steam Service |
| Testing Standards | ASME B16.34, API 598, High-Pressure Hydrostatic Shell & Seat Tested |
High Pressure Steam Service Configurations
| Type & Model | Key Features & Operating Applications |
|---|---|
| Supercritical Steam Isolation Valves | Class 2500# P91/C12A alloy gate valves for modern thermal power plant main steam lines. |
| Boiler Feedwater Gate Valves | Class 1500# high-pressure water pump discharge isolation valves with erosion-resistant hardfacing. |
| Parallel Slide Pressure Seal Valves | Parallel seating discs that eliminate thermal wedge binding during boiler cool-down and warm-up cycles. |
| Motorized High-Pressure Valves | Equipped with high-torque electric multi-turn actuator for remote boiler emergency shutoff. |