IBR Blowdown Globe Valves and Form III-C in India
Technical guide · Supreme Valves India · Updated 2026-10-28
Direct answer: Continuous blowdown service on Indian IBR boilers typically needs a forged Class 800 OS&Y globe with hardfaced (Stellite) seats and IBR documentation (often Form III-C). Write IBR + form + hardfacing scope on the RFQ before production starts.
Typical construction
| Parameter | Common blowdown callout |
|---|---|
| Type | Globe, OS&Y, bolted bonnet |
| Body | Forged A105 / A105N |
| Class / ends | Class 800, SW or NPT |
| Seat / disc | Stellite hardfaced |
| Docs | IBR Form III-C (as applicable) + 3.1 MTC |
Archive BOQ examples
CONTINUOUS BLOWDOWN GLOBE VALVE, FORGED CS ASTM A105, SOCKET WELD, CLASS 800SEAT IN-SITU STELLITED, DISC SS410 + STELLITE
RFQ checklist
- IBR yes + form required
- Size, SW/NPT, Class 800
- Stellite seat and disc
- Test / witness requirements
Pattern page: A105 Class 800 globe RFQ.
Frequently asked questions
What is Form III-C?
An IBR documentation form used in Indian boiler practice for certain fittings/valves. When the project is under IBR, state Form III-C (or the form the inspector requires) on the RFQ so certificates are prepared correctly.
Why Stellite on blowdown globes?
High-velocity flashing condensate erodes soft seats. Hardfaced (Stellite) seats and discs are standard on continuous blowdown tags.
Are blowdown valves usually Class 800 forged?
Yes on many packages — forged A105 Class 800 SW OS&Y globes. Confirm class and ends from the boiler piping design.