タイトルまたは説明

Body vent and drain
The drain and vent plug of the valve body enable to check the integrity of the seat ring. A bleed valve may replace the drain plug.

Double block and bleed
BOTELI design of a valve with two seating surface between which the cavity can be vented through a bleed connection and thus confirm the tightness of the valve, as well in closed position as open positon, when pressure is applied to any side or both sides of the valve.

Double piston effect
With the DPE seat configuration when  there is a leakage in the upstream seat, the pressure entering into the body cavity pushed the downstream seat against the ball and the valve seals.
This effect is a sealing principle involved in utilising line pressure to effect a seal across the floating seat.

Self relieving seat
In self relieving condition, excessive internal body pressure is automatically relieved both in upstream and downstream line by forcing the seats away from the closure element.