The Parker Prädifa piston sealing set profile ZQ was developed from our profile ZC. It is especially suitable for use in telescopic legs with the bottom value. This sealing set consists of a one-part rubber-fabric sealing ring and very sturdy “semi-active” back-up rings. The dynamic surface of the seal is reinforced with a special fabric, retaining favourably the lubricating film between seal and cylinder wall, even after long standstill periods under high pressure. The breakaway friction and the dynamic friction will be considerably less wear of the seal.

Field of application:

Working pressure: ≤ 1500 bar
Working temperature: HFA-, HFB, and HFC-fluids: +5 to 60 ºC Mineral oil: -20 to +80 ºC

Surface speed: ≤ 0,1 m/s

Mainly for double-acting pistons in hydraulic props and tunneling machines.

Installation:

The Parker Praedifa sealing sets ZQ … 00250 and ZQ … 00270 are for use on one-piece pistons. The Sealing Sets of the series ZQ … 00254 and ZQ … 00274 require open housing (divided piston). To avoid damaging
care should be taken that the seals are not pulled over sharp edges during installation.

Compounds:

Standard compound for the sealing partis an NBR-based elastomer (Z5017) with the fabric-reinforced dynamic surface (SEW-compound). The back-up rings are made of a polyacetal-based material (W5001).

For special requirements (pressure, temperature, speed, etc.) please contact our Consultancy Service, so that suitable materials and/or designs can be recommended.