IS 554 vs BS 21 pipe threads: what to check before you buy a brass valve

Short answer: IS 554 (Indian standard) and BS 21 (British standard) both describe pipe threads on valves and fittings where the thread itself makes the seal. Before you order, confirm the thread type your pipes use.

What can go wrong

• A tapered male thread with a straight female thread is a normal pairing, sealed with PTFE tape.
• BSP and NPT (American) threads look similar but do not match. Do not force them together.
• Sizes are nominal: a 15 mm (1/2 inch) valve is a pipe size, not the actual thread diameter.

Checklist before you order

1. Pipe size in mm and inch (15, 20, 25, 32, 40, 50 mm).
2. Thread type your pipe fittings use (BSP or NPT).
3. Product and use: brass ball valve, CPVC union ball valve, check valve (NRV), nozzle bib cock, CP control valve or 3-way valve.
4. Quantity: minimum 200 pieces per carton.

What M-Tech Valves supplies

Brass ball valves, CPVC union ball valves, check valves (NRV), angle valves, nozzle bib cocks, CP control valves, 3-way valves and CP extension nipples. Tell us the thread you need when you ask for a quote.

Call or WhatsApp +91 77550 01116. All products carry a 5-year warranty for breakage and leakage.

See the full range at www.m-techvalves.com.