Globe valves: how to choose for steam, water and oil products
The globe valve is the workhorse for small and medium steam lines, drains, blowdowns and any point that is opened and closed often. These are the selection points.
TAZ Engineering Team · · 6 min
Body material
Carbon or alloy steel for high-parameter steam and hot water. Cast iron is acceptable for low-parameter water and steam but not for gas or flammable media. Stainless steel for corrosive service.
Disc and seat
A flat disc gives good shut-off but poor throttling; a profiled or needle disc throttles better. Seats are stainless or hardfaced for steam; soft seats suit water at moderate temperature.
Packing or bellows
Standard globe valves seal the stem with packing. Bellows-sealed valves add a metal bellows around the stem and practically eliminate external leakage, for toxic, explosive or high-value media.
Installation
Install strictly to the flow arrow, usually with flow under the disc. Reverse installation increases opening force and impairs operation. Leave access for gland maintenance.
Ordering
State the medium, DN, PN, temperature, end connection, throttling need and bellows requirement. TAZ makes steel globe valves 15s22nzh and 15s65nzh.
Checklist
- medium and temperature
- DN and PN
- body material
- disc type
- packing or bellows
- end connection
- flow direction