PTFE Lined Ball Valve

It is a quarter-turn valve whose entire wetted surface — body, ball and stem — is lined with PTFE, so the process media never touches the metal. A one-piece integral ball-stem rotates 90° inside a replaceable PTFE seat to give bubble-tight shutoff, and the full-port, split-body two-piece construction means no flow restriction.

Operation is by manual lever up to 100 mm and worm gearbox from 150 mm upward, with pneumatic actuators available. The glandless live-loaded design keeps torque well below an equivalent plug valve, needs no gland packing adjustment, and leaves no backlash between stem and ball after prolonged service.

Body options are Ductile Iron GGG40.3 / ASTM A395, Cast Steel ASTM A216 Gr. WCB, ASTM A351 Gr. CF8 (SS 304) and Gr. CF8M (SS 316). Lining options are PFA (ASTM D3307), FEP (ASTM D2116), PVDF (ASTM D3222), PP (ASTM D4101) and HDPE, applied at 3–5 mm thickness. The seat ring, sphere bush and flexible diaphragm are PTFE.

PTFE covers most chemical service. Specify PFA where the media is highly permeating — chlorine, bromine or fluorine — or where higher temperature and a full vacuum rating are needed. Because the liner is what seals, flange bolts must be tightened evenly in a cross pattern: over-torquing damages it.

Sizes run from ½″ to 10″ (DN 15–250) at a PN10 nominal rating. Flange drilling is to ASA #150, DIN 2632/2633, BS 10 Table D, E or F, or customer-specified, with face-to-face dimensions per ANSI B16.10 / BS EN 558-1/2.

The working temperature depends on the liner: PTFE −20 °C to +180 °C, PFA up to 260 °C, FEP up to about 150 °C, PVDF up to about 140 °C and PP up to about 90 °C. Derate the pressure as temperature rises.

The valve is designed to BS EN ISO 17292:2004 (formerly BS 5351) and tested to BS EN 12266-1 & 2 (2003) — hydraulic shell test 20 kg/cm², hydraulic seat test 11 kg/cm² and pneumatic seat test 6 kg/cm² — plus a 15 KVDC spark test on every valve to confirm the lining carries no pinholes.

Both are quarter-turn and fully lined, so both suit corrosive duty. The ball valve operates at significantly lower torque and its full-port bore does not restrict flow, which makes it the better general-purpose choice for on/off service on clean acids, solvents and chemical transfer lines.

A sleeved plug valve seals better in slurry and frequent-cycling duty, where a sleeve tolerates particulate that would score a ball seat, but it needs more torque to operate. For most corrosive isolation duty the ball valve is the default.

MVS has manufactured valves since 1978 — a manufacturer, not a trader — is ISO 9001:2015 certified, and exports across several continents. The minimum order quantity is 20 pieces.

Custom body and lining combinations, special flange drilling and fully actuated assemblies are built to order. The seat ring and diaphragm are field-replaceable, so a valve can be serviced in place rather than replaced. Send us your media, operating temperature, line size and pressure and we will confirm the specification and delivery schedule.