Parallel Slide Blow Down Valve -- PN16 WCB/CS
Technical Datasheet -- Boiler Blow-Down and High-Pressure Drain Valve
Document No.SV-DATA-PSBD-001
RevisionA
DateMay 2026
ManufacturerSupreme Valves India, Ahmedabad, Gujarat, India
Parallel slide blow down valves for boiler blow-down and high-pressure drain service. The parallel slide disc design eliminates the seat scoring common in wedge gate valves during throttling and particle-laden blow-down cycles. Spring-loaded SS316/Stellite disc plates ensure tight shutoff across the full temperature range, even after repeated thermal cycling.
Technical Specifications
| Parameter | Specification |
|---|
| Product Type | Parallel Slide Blow Down Valve |
| Category | Specialty Valves |
| Size Range | 2" to 12" (DN50 to DN300) -- other sizes on request |
| Pressure Rating | PN16 (other ratings on request: PN25, PN40, Class 150, Class 300) |
| End Connections | Flanged EN 1092-1 (PN16) or ASME B16.5 Class 150 RF |
| Body Material | ASTM A216 WCB Carbon Steel Casting |
| Disc / Seat Plates | SS316 Stainless Steel with Stellite overlay on seating surface |
| Stem Material | ASTM A276 316 Stainless Steel with anti-blowout design |
| Packing | Graphite braided packing with live-loading -- fire-safe and steam-compatible |
| Gasket | Spiral wound SS316/graphite per ASME B16.20 |
| Bonnet Type | Bolted bonnet with extended neck for high-temperature insulation |
| Operation | Handwheel (standard) -- gear operator or electric actuator for large sizes |
| Temperature Range | Up to +425 deg C (WCB body) -- up to +540 deg C with WC6 body |
Materials of Construction
| Component | Material |
|---|
| Carbon Steel | ASTM A216 WCB, A105 |
| Stainless Steel | SS316 disc and seat plates, A276 316 stem |
| Overlay | Stellite 6 on seating surface for erosion resistance |
| Packing | Graphite braided with live-loading (steam-compatible) |
Testing & Inspection
| Test | Requirement |
|---|
| Testing | Hydrostatic shell test 1.5 x WP per EN 12266-1 / API 598; Seat leakage test per EN 12266-1 / API 598; Functional test -- full stroke, tight shutoff after repeated blow-down cycles |
| Certification | ISO 9001:2015 QMS, EN 10204 3.1 material certificates, hydrostatic and seat test reports |
Applicable Standards
| Standard | Description |
|---|
| Design Standard | BS 1873 / DIN 3356 Globe Valve pattern adapted for parallel slide blow-down service |
Notes
- All valves are manufactured by Supreme Valves India as per our standard specifications.
- For high-temperature steam service (> 425 deg C), material upgrade to ASTM A217 WC6 body is required.
- For frequent blow-down cycles (> 1 per day), Stellite 6 overlay on both disc and seat plates is strongly recommended.
- Gear operator or electric actuator is recommended for valves 8 inch and larger due to operating torque.
- All valves are factory-tested per EN 12266-1 / API 598: hydrostatic shell test 1.5 x design pressure, seat leakage test per EN 12266-1 / API 598, functional test (full stroke, tight shutoff after repeated cycles).
