PR Plug Valves for low pressure Type 1
The PR-Plug valves are tough and compact. They are designed for ambitious behaviour in operation with nearly endless lifetime.
The required space is low - even in huge dimensions. The construction is uncomplicated and straight.
Plug
The only moving part is the plug. Each plug is produced to fit perfectly in the body. This precise adjustment and the constant lubricating film between body and stem prevents intrusion of particles inside and protect the valve for leaking and damage.
The cylindrical shape features the advantage that the plug do not can be moved easy at any time.
Bore
The standard bore is rectangular with full or reduced bore. The reduced bore is normally one dimension less than the connection dimension. The rectangular bore is used to create a compact and economically valve.
For special use (like pigging) full round bore is available, too. Shape and dimension correlate to the pipeline dimension.
Lubrication System
One essential distinguishing feature is the lubrication system. This system is an important element of the construction and meet safe and durable its function for proper use and tightening the valve inside and to the outside.
The plug valve can be lubricated at any time and riskless in operation from outside. The lubrication system has also other excellent properties, which are not reached from other sealing systems (metal/metal or soft sealings):
- No corrosion and erosion at the sealing surface.
- No metal/metal contact and smooth-acting control even after long periods of service interruption.
- Insensetive against particles.
- No need for repairing the sealing surfaces - no need to disassemble the valve.
- Flexible and easy movable sitting in the body.
- Heat resistant up to + 250°C.
- Abslute safe sealing over decades without disruption.
Profile ring
The PR cylinder valve is glandless. Sealing to the outside is provided by the sealant and additionally by a maintenance-free profile ring made of Perbunan or PTFE with a stainless steel spring on the cylinder shaft. These rings can withstand thousands of switching operations, as the switching path of the valve is short and the design prevents vertical abrasion due to sliding or rolling. The profile ring does not work as a pressure-bearing element, has no contact with the flow medium and is therefore not a wearing part.
Operation
The open or closed position of the PR plug valve is achieved by turning the plug by 90° to the limit stop. In the case of small nominal sizes (see data sheets), the valves are normally operated with a handle, otherwise worm gear drives enable manual operation or additional electric, pneumatic or hydraulic drives enable automatic operation.
In all nominal sizes, clearly visible indicators mark the respective plug position.