DN25 GLOB VALVE FOR STEAM

*DN25 Globe Valve for Steam* = 1 inch globe valve for steam line. DN25 = 25mm bore = 1″ pipe.

Globe valve = For throttling / controlling steam flow – Not for on/off only. For on/off, use gate valve or ball valve. For control, use globe.

### *DN25 Globe Valve for Steam Specs*
Spec Details
**Size** DN25 = 1″ = 25mm
**Connection** BSP female thread or Flange PN16 / PN40
**Media** Steam, hot water
**Pressure** PN16 = 16 bar / PN40 = 40 bar – For steam must be PN40
**Temp** Up to 300°C – For steam 180°C – 250°C
**Body** Cast steel WCB / Stainless SS304 – **NOT brass for steam >150°C**
**Disc / Seat** SS304 – Hard seat, no leak
**Stem** SS304
**Seal / Packing** PTFE + Graphite – For steam
**Handwheel** Cast iron, red
**Flow** Straight pattern – Pressure drop 2x gate valve
### *Price Lagos Oct 2025*
Type Pressure Body New Price Used Price Quality
**DN25 Globe Threaded Brass** PN16 16 bar Brass ₦18k – ₦28k ₦10k – ₦15k 5/10 – Only for low steam <150°C, not for boiler
**DN25 Globe Threaded Cast Steel WCB** PN40 40 bar WCB Steel ₦45k – ₦65k ₦25k – ₦35k 8.5/10 – **Most sold for steam**
**DN25 Globe Flanged Cast Steel WCB** PN40 40 bar WCB Steel ₦55k – ₦80k ₦30k – ₦45k 8.5/10 – For boiler line
**DN25 Globe Flanged SS304** PN40 40 bar SS304 ₦95k – ₦140k ₦55k – ₦80k 10/10 – Best, no rust, 10yrs
**DN25 Globe Flanged SS316** PN40 40 bar SS316 ₦130k – ₦180k ₦75k – ₦110k 10/10 – Chemical steam
**DN25 Globe Germany KSB / ARI** PN40 WCB / SS ₦220k – ₦320k ₦120k – ₦180k 10/10 – Original
*Best value*: *DN25 Globe Threaded Cast Steel WCB PN40 ₦55k New* – For steam 10-15 bar boiler.

### *Threaded vs Flanged DN25*
**Threaded DN25 Globe ₦55k** **Flanged DN25 Globe ₦70k**
**Connection** Screw onto 1" pipe – Teflon tape Bolt to flange – Need 2x flange + gasket + bolts ₦15k extra
**Install** Easy, 10 mins 30 mins, need welder for flange
**Leak** Can leak if thread bad No leak if gasket good
**Pressure** PN40 OK PN40 OK, safer
**For** **Small steam line <2" – Buy threaded** **Boiler main line, big factory – Buy flanged**
*For DN25 small line, threaded is enough and cheaper.*

### *Globe vs Gate vs Ball for Steam DN25*
Valve Use Price DN25 Pressure Drop Leak For Steam?
**Globe DN25** **Throttling / Control flow** **₦55k** High – 2 bar drop Very low leak **✅ Best for controlling steam flow**
**Gate DN25** On/Off full open ₦45k Very low – 0.2 bar Medium leak after 1yr ✅ For main on/off
**Ball DN25 SS** On/Off fast ₦35k Very low Low leak ⚠️ Only if PTFE seal, max 180°C – Not for 250°C steam
**Butterfly DN25** On/Off ₦40k Low Medium ❌ Not for steam high temp
*Rule: If you need to half-open to control steam, buy globe. If you only need full open / full close, buy gate – Cheaper and less pressure drop.*

### *Steam Temp / Pressure Chart*
Boiler Pressure Steam Temp Valve You Need
**5 bar** 152°C PN16 WCB OK, brass borderline
**8 bar** 170°C PN40 WCB – Brass will fail
**10 bar** 184°C **PN40 WCB – Standard**
**15 bar** 198°C PN40 WCB / SS304
**20 bar** 212°C PN40 SS304
*Most Lagos boilers are 8-10 bar. Buy PN40 WCB.*

### *Installation for Steam DN25*
1. *Direction*: Arrow on body = steam flow direction. Globe valve only works one way. Reverse = won't close
2. *Position*: Install with stem horizontal or vertical up – Not stem down – Condensate collects in bonnet if stem down
3. *Before valve*: Install Y-strainer DN25 ₦18k before globe – Dirt scratches seat, valve leaks
4. *After valve*: Install steam trap after globe if long line – Removes condensate
5. *Teflon*: Use PTFE tape + high temp sealant – Normal thread seal melts at 180°C
6. *Support*: Support pipe, don't let valve carry pipe weight – Body cracks

### *Key Tips*
1. *Don't use brass for boiler steam*: Brass softens at 200°C, body can burst at 10 bar. Use WCB steel
2. *Don't use ball valve for throttling steam*: Ball valve half-open vibrates, seat erodes in 1 month. Use globe for throttling
3. *Spare gasket*: Buy graphite gasket set ₦5k – Packing leaks after 6 months, you re-pack, not buy new valve
4. *Insulate*: Lag valve with insulation – Bare DN25 globe loses 300W heat, wastes diesel
5. *Open fully when not throttling*: If you use globe as on/off, open fully – Half-open erodes seat fast

*Bottom line*:
For boiler steam 8-10 bar, 1" line → *DN25 Globe Valve Threaded Cast Steel WCB

What is your boiler pressure – 8 bar, 10 bar, or 15 bar? And do you need threaded or flanged? And is it for controlling flow (throttling) or just on/off? I’ll tell you if globe is right or gate valve is cheaper and better for you.