custom pneumatic seal

Custom Pneumatic Seal Selection, Sizing, and RFQ Data

Quick Answer: A custom pneumatic seal is specified when a cylinder uses a non-standard bore, rod diameter, groove width, or operating condition that catalog seals cannot cover. Send CORASEALS the bore diameter, rod diameter, groove dimensions, operating pressure, temperature, media, and seal profile. We will check the seal section, material, and tolerance before quotation.

Custom pneumatic seals are used in pneumatic cylinders, valve actuators, factory automation equipment, and air tool repair. Standard pneumatic seal catalogs cover many metric and inch sizes, but real cylinders can be worn, modified, imported, or built to non-standard dimensions. A custom pneumatic seal allows the seal profile and material to match the actual cylinder hardware.

CORASEALS supplies custom pneumatic seal types as replacement parts and as components for cylinder service programs. The main products include pneumatic rod seals, pneumatic piston seals, pneumatic wiper seals, O-rings, and custom machined lip seals. We focus on seal geometry first, not only on part numbers.

When a Custom Pneumatic Seal Is Required

A custom pneumatic seal may be needed in the following situations:

Metric cylinder dimensions do not match common ISO or DIN pneumatic cylinder sizes.
Inch bores, rods, or grooves require ID, OD, and width conversion.
The original seal compound must change from NBR to FKM or another material.
The groove is shallow, wide, worn, or not listed in a standard seal catalog.
A special lip shape, wiper geometry, or non-standard section is required.
A continuous production part is needed with controlled dimensions and packaging.

In these cases, a standard pneumatic seal may fit loosely, pinch, or wear early. The custom option matches the seal section to the actual cylinder hardware.

Pneumatic Seal Profiles for Custom Production

Pneumatic rod seals keep air inside the cylinder while the rod moves. They are often single-acting lip seals or compact U-cup profiles. The rod seal must operate with low friction and tolerate some side load if the rod alignment is not perfect.

Pneumatic piston seals are installed on the piston and seal between the piston OD and the bore. They commonly use low-friction NBR or polyurethane lip profiles. The groove width is critical because a narrow groove can pinch the seal and a wide groove can allow extrusion.

Pneumatic wiper seals remove dust and moisture from the rod during retraction. They protect the rod seal from contamination. In dusty or dirty factory air, a custom wiper may need a different lip angle or a harder compound.

O-rings are used for static sealing on end caps, sleeves, and valve bodies in pneumatic systems. Custom O-ring sizes can be produced for non-standard inside diameter and cross section requirements.

Material Selection for Custom Pneumatic Seals

NBR and polyurethane are common for general pneumatic cylinder service. FKM is specified when the seal sees higher temperatures or aggressive chemicals. EPDM is not suitable for most mineral oil lubricated air systems because petroleum oil can degrade EPDM. Silicone is rarely used for dynamic pneumatic lip seals because of its low tear strength, but it can be used in some static or low-load applications.

Some polyurethane compounds can be sensitive to hot water and hydrolysis. If the air system has high condensation, washdown cleaning, or chemical exposure, the compound must be checked. Do not choose a material only by color or hardness. Provide the air temperature range, lubrication condition, cleaning chemicals, and required Shore A hardness.

Dimensions and Measurement Data Required

For a custom pneumatic seal quotation, send the following information:

Bore diameter
Rod diameter
Groove ID or groove OD
Groove width
Seal type, such as rod seal, piston seal, or wiper seal
Section shape or existing sample photo
Operating pressure, temperature, and media
Required quantity

If the seal is for a repair job, provide the original part number and the measured cylinder dimensions. A part number alone is not enough because pneumatic seal part numbers can include compound and profile codes that differ between suppliers.

Operating Conditions and Surface Finish

Pneumatic sealing usually involves lower pressure than hydraulic sealing. The maximum working pressure must be confirmed for each cylinder. Speed and cycle rate also matter because high cycling can generate heat at the lip contact area. If the cylinder runs at high speed, the seal material and lip geometry may need adjustment.

For rod seals, the rod surface finish, hardness, and runout affect seal life. If the rod is scratched or the chrome plating is damaged, a new custom pneumatic seal will not stop the leak. The rod surface must be checked together with the seal replacement.

Why Use CORASEALS for Custom Pneumatic Seals

CORASEALS is a global industrial seal supplier and custom pneumatic seal supplier for replacement and OEM requirements. We prepare custom pneumatic seal quotations based on the groove dimensions, seal profile, material, and quantity. We do not rely only on standard part numbers. We support customers that need non-standard sizes, trial batches, and replacement seals for imported or legacy pneumatic cylinders.

If the seal profile is unclear, send a drawing or sample photo. We can compare the section shape and lip direction against common pneumatic seal profiles. If the required part is outside our current product range, we will tell you before quotation instead of forcing an incorrect standard part.

FAQ

What is a custom pneumatic seal?
A custom pneumatic seal is a rod seal, piston seal, wiper seal, or O-ring made to fit non-standard cylinder dimensions, grooves, or operating conditions. It is specified by bore, rod, groove, material, and lip profile rather than only by a catalog part number.

Can CORASEALS make a pneumatic seal from a sample?
Yes. Send a sample photo, drawing, and the measured ID, OD, and width. We will check the lip direction, section shape, and material before quoting a replacement or custom production batch.

What information is needed for a custom pneumatic seal quotation?
Provide the bore diameter, rod diameter, groove dimensions, operating pressure, temperature, air lubrication status, media, seal profile, and required quantity. For repair jobs, also send the original part number if available.

Which material is best for a pneumatic cylinder seal?
NBR and polyurethane are common for general pneumatic service. FKM is used for higher temperatures or chemical exposure. The best material depends on temperature range, air lubrication, condensation, and cleaning chemicals.

Does CORASEALS stock custom pneumatic seals?
Custom seals are produced against confirmed dimensions and order quantity. Standard sizes may be available. Send the required dimensions, material, and quantity, and we will confirm the quotation and production lead time.

Request a Custom Pneumatic Seal Quotation

Send us the bore diameter, rod diameter, groove dimensions, operating pressure, temperature, media, seal profile, drawing, sample photo, and required quantity. We will review the information and return a specific seal recommendation for your pneumatic cylinder or application.

If you need a related part, see our custom pneumatic seal options or view pneumatic seal profiles before sending your inquiry.