Product description:

ASME B16.34,ISO 17292 design standard

Features:

Low Emission Packing

The packing is combination of parallel and vertical layer

which is made of die-formed graphite ring processed by

flexible graphite, characterizing heat resistance, less

stress relaxation and low creep. The special structure

means low friction on rotary stem, providing stabilized

seal capability for the valve for a long time under frequent

functioning.

For low-temperature and cryogenic service, the standard

V shape PTFE packing rings are installed for low

emission control.

Fire Safe - Metal to Metal Sealing

When soft seats are decomposed or ruined by fire, the ball,

driven by pressure, comes into contact with the metal lip seal

seat of original soft seat, creating a metal-to-metal seal to

shut off service fluids and minimize internal leakage.

Additionally, the fire safe metal seat prevents damage the

medium imposed on soft seat and minimizes creep of nonmetal

materials. All the Cowinns floating valves are designed to be fire

safe per API 607 and are tested and certified by the third party

Roughness control over stem and packing

Stem surface roughness is strictly restricted between

Ra0.4 and Ra0.8, which ensures entry of graphite

packing powder into tiny stem scratches to function as a

lubricator, minimizing leakages around stem. Max.

roughness of stuffing box is RA3.2, which is a proper

value to hold packing ring in place and result in better

sealing performance

Anti-static Device

A spring-loaded plunger fitted on stem keeps constant

contact between ball, stem and body to create an electric

path to transfer charges, avoiding acceleration of static

electricity as a result of friction during valve on-off. Such

build-up is utterly hazardous to some services.

Blow-out Proof Stem

The lower end of the stem is T-shaped structured, protected

by boss of body, which assures stem retention at any

pressure and acts as backseat.