Piston Seals

Double acting and single acting.

MDD / IDD

MDD is a double acting plain seal with L-shaped wear rings consisting of a precision moulded fabric reinforced nitrile sealing element.

As with all this rang it is designed for use on a split piston.

The fabric helps prevent extrusion whilst retaining some of the sealing media to reduce friction.

The wear rings help prevent extrusion, permit higher working pressures and allow larger clearances between the piston and cylinder. They also support the piston under side load conditions therefore preventing metal to metal contact.

These seals are available:

Double acting plain
Double acting plain with L-shaped wear rings
Double acting with anti-extrusion rings on the outside
Double acting with clip-on L-shaped wear rings

MD-GR-EO / ID-GR-EO

The seal is a precision moulded Nitrile rubber sealing element with a proportional bonded reinforced fabric base, and an acetal back up ring to resist extrusion. The acetal anti-extrusion ring allows larger clearances and higher pressures. Designed to provide effective low pressure sealing through distortion of the lips rather than "squeeze". This gives an improved response to pressure variations and reduces low pressure stiction to ensure a smoother return stroke. The seal is designed with initial radial interference to effect low pressure sealing. The rubbished fabric header has the advantage of retaining fluid within its surface thus reducing both friction and wear.

MD - EO / ID - EO

A precision moulded Nitrile rubber sealing element with a reinforced fabric base and an acetal back up ring to resist extrusion. The acetal back up ring allows larger clearances and higher pressures. The seal is designed with initial radial interference to effect low pressure sealing. At higher pressures the seal is energised thus increasing sealing. The rubberised fabric header has the advantage of retaining fluid within its surface thus reducing both friction and wear.

MD-LW / ID-LW

Produced with initial radial interference to effect low-pressure sealing, the seal is progressively energised at higher pressures thereby increasing the sealing force. Rubberised fabric has the advantage of retaining the sealing media within its surface, thus reducing friction and wear. The width polyacetal bearing ring resists extrusion of the seal to allow greater clearances and higher pressures.

PCM-Bronze / PCI-Bronze

Designed as high pressure, low friction Double-acting piston seals for use in heavy duty hydraulic and pneumatic cylinders.

These are also available as a single acting two part seal stepped PTFE sleeve with an O-ring energiser.

MGD / IGD

Nitrile rubber sealing element with a proportional bonded reinforced NBR header and an acetal bearing ring to resist extrusion. The acetal bearing ring resists extrusion of the seal to allow greater clearances and higher pressures, and provides bearing support for the piston preventing misalignment and metal to metal contact between piston and bore.

SPW - Metric - Imperial

Designed for use on one piece pistons, the seal assembly consists of a filled PTFE high performance outer sleeve, pre loaded and pressure energised by a precision moulded NBR element. These two components are protected from extrusion at either side by the fitting of two low friction plastic anti-extrusion rings making the seal highly resistant to shock loads as found in heavy duty mobile equipment.

PCM-SQ-Polyurethane / PCI-SQ-Polyurethane

Designed for use on one piece pistons. The seal consists of a precision moulded high performance 98 Shore Polyurethane outer sleeve, pre loaded and pressure energised by a square section NBR 80 Shore rubber element. The impact design allows smaller width pistons to be used. The seal offers excellent wear resistance on a wide range of surface finishes.

PCM-Polyurethane / PCI-Polyurethane

Designed for use on one piece pistons. The seal consists of a precision moulded high performance 98 Shore Polyurethane outer sleeve, pre loaded and pressure energised by an O-ring energiser. The impact design allows smaller width pistons to be used. The seal offers excellent wear resistance on a wide range of surface finishes.

MSPS / ISPS 5 Part

Designed for use on one piece pistons, the five part assembly consists of an endless precision rubber moulded sealing element supported at each end with angle split support rings. The support rings are designed to accommodate split Polyacetal anti-extrusion bearing rings.

The design allows the anti extrusion bearing rings to react positively to increasing pressures. The final assembly provides a robust sealing unit designed to operate at higher pressures.

The seal is also suitable for existing two piece pistons of the same housing dimensions.

Operating Conditions 5 piece

Max Speed Temp Range

m/s -30 deg to 100 deg

0.50 300 bar

0.15 400 bar

MSPS / ISPS 3 Part

The 3 part is a light duty seal designed for a solid piston. Consisting of a precision moulded Nitrile sealing element with two split Polyacetal wear rings.

Operating Conditions 3 piece