Company Profile

Pneumatic Seals Manufacturer in China: Pneumatic Cylinder Seal Types, Materials, and Quotation Checklist

Quick Answer: CORASEALS supplies pneumatic seals from China for global buyers. The range includes piston seals, rod seals, wiper seals, scraper seals, O-rings, backup rings, wear rings, guide rings, and pneumatic cylinder seal kits. Send cylinder bore, rod diameter, groove dimensions, medium, pressure, temperature, speed, material, drawing, sample photo, and quantity to request a pneumatic seal quotation.

Pneumatic Seal Types CORASEALS Can Supply

Pneumatic cylinders use different seal profiles at different positions. A piston seal seals between the piston and cylinder bore. A rod seal seals between the cylinder head and the piston rod. A wiper seal or scraper seal stops dust and moisture from entering the cylinder. Wear rings and guide rings support the piston and rod against side load.

CORASEALS supplies pneumatic piston seals, rod seals, wiper seals, scraper seals, O-rings, backup rings, wear rings, guide rings, and complete pneumatic cylinder seal kits. The seals can be matched to standard cylinder housings or custom machined to a customer drawing.

Common seal profiles include single lip U-cup seals, O-ring loaded U-cup seals, compact piston seals, rod lip seals, and PTFE based wear rings. The correct profile depends on the groove shape, the cylinder bore, the rod diameter, and the operating conditions.

Pneumatic Seals vs Hydraulic Seals

Pneumatic seals operate under different conditions than hydraulic seals. Compressed air systems usually work at lower pressure than hydraulic systems. Air cylinders often run with less internal lubrication, especially when the system uses dry air. The seal must balance sealing force and friction. A seal that works well in hydraulic oil may create too much friction in a pneumatic cylinder.

Hydraulic seals focus more on high pressure extrusion resistance and fluid film control. Pneumatic seals focus more on low friction, wear life, and clean operation. CORASEALS evaluates the medium and the cylinder condition before recommending a seal profile.

Material Selection for Pneumatic Seals

Pneumatic seal material selection starts with the compressed air condition and the cylinder lubrication method. NBR is a common choice for air with oil mist and normal temperature. Polyurethane or TPU often provides better wear life and lower friction under clean air conditions. FKM is used when the compressed air has higher temperature or contains aggressive synthetic oil. EPDM works in oil-free air and has good ozone resistance. EPDM is not suitable for most mineral oil lubricated systems. PTFE is used for wear rings, backup rings, and low friction applications.

Do not select a pneumatic seal by material only. The material must match groove dimensions, cylinder pressure, rod speed, cycle frequency, and the surface finish of the mating parts. A seal that works in a slow moving cylinder may fail in a high cycle cylinder with dry air.

O-rings and Static Sealing

Many pneumatic cylinders also use O-rings for static sealing on end caps, ports, cushion adjusters, and rod wiper housings. O-ring grooves should follow the standard size and tolerance for the chosen O-ring. CORASEALS supplies O-rings in AS568, ISO 3601, and JIS B 2401 sizes. Custom O-ring dimensions are also available.

For dynamic pneumatic O-ring applications, check the running clearance and use a backup ring where needed. The backup ring prevents extrusion under pressure peaks.

Dimensions and Profile Codes

Pneumatic seal buyers often ask by cylinder model or profile code. Codes can help identify seals, but the same code may have different meanings in different supplier catalogs. CORASEALS verifies each seal by groove ID, groove OD, groove width, groove depth, rod diameter, and bore diameter.

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