Plug Valves

Lubricated plug valves inject a sealant compound between the plug and the body bore: the sealant fills micro-surface imperfections, reducing operating torque and providing sealing. They are suited to gas distribution, sour service (H₂S), and abrasive slurry where metal-to-metal contact would seize. Non-lubricated (PTFE-sleeved) plug valves use a PTFE or PFA sleeve liner as the seating surface - self-lubricating, no sealant required, maintenance-free, and preferred for chemical service where sealant contamination is unacceptable.

Yes - plug valves provide bi-directional shut-off because both upstream and downstream port faces of the tapered or cylindrical plug contact the body bore. This makes them suitable for applications where flow can reverse direction - pipeline manifolds, compressor station bypass lines, and crude oil gathering systems with back-pressure surges. For bi-directional gas service, specify a pressure-balanced lubricated plug valve which uses equalised line pressure to help maintain plug-to-body contact.

A 3-way plug valve is used to divert, mix, or switch flow between two pipeline circuits from a single valve body. T-port configuration: with one inlet and two outlets, the T-port can direct flow to either outlet independently or - at 45° - simultaneously to both (mixing or splitting). L-port configuration: connects inlet to one outlet only (full diversion). Common applications: tank switching manifolds, heat exchanger by-pass switching, sampling line selection, and chemical dosing manifolds.

Lubricated metal-to-metal plug valves are inherently resistant to fire - there are no elastomers to fail. PTFE-sleeved plug valves lose their sleeve seal in fire conditions; fire-safe versions with a secondary metal seat and graphite packing backup are available and tested to API 607 for critical hydrocarbon service. If your application is in a classified hydrocarbon service area, confirm whether a fire-safe certification is required by your plant engineering standard before ordering.