The PPD-12 profile
These pneumatic seals are the PPD-12 double-acting nitrile piston-seal type. The specification sheet places the PPD family in applications with low axial housing heights and identifies certain short-stroke applications. This page covers the 12 mm bore size only, rather than a selectable range of similar-looking seals.
Read the installation dimensions correctly
The PPD-12 row specifies a 12 mm bore, a 7.4 mm groove diameter, a 1.8 mm nominal groove height and an 11.7 mm nominal piston diameter. Those are dimensions of the installation shown in the drawing. In particular, the 7.4 mm groove diameter must not be presented as a measured inside diameter of a loose seal.
The groove-height tolerance is +0.2/−0 mm, and the piston-diameter tolerance is +0/−0.1 mm. Keep each tolerance with its named feature. When comparing your cylinder drawing, check the complete PPD-12 row instead of selecting a replacement on the basis of the bore alone.
Operating conditions and the illustrated profile
The PPD specification sheet lists pressure up to 168 psi and a temperature range of −20°F to 220°F. These are the published seal-family limits, not a statement that every cylinder operating anywhere within that range is compatible. The application still needs the correct housing, operating medium and installation design.
The product illustration uses a cutaway to explain the profile. The supplied seal is continuous; the illustrated gap is not a split in the part. The source sheet shows other seal families nearby. Their profiles and rows should not be substituted for PPD-12 simply because the bore size appears similar.
Compare pneumatic seals by the complete reference
Have the original part reference and cylinder drawing available when assessing a replacement. Check bore, groove geometry, piston diameter and the required double-acting construction together. This page does not include a piston, cylinder, rod wiper or complete repair kit. Another bore size or profile would need its own exact product reference.
For an uncertain replacement, keep the uncertainty open rather than modifying the part number in your request. We will confirm the requested product and supply terms before any purchase. A dimensional resemblance or a rendered image does not establish engineering interchangeability.
Request a four-seal pack
One proposed Plethara pack represents four PPD-12 seals. Requested quantity means packs; two packs represent eight seals of this SKU. The grouping does not promise supplier packaging, inventory or a delivery date.
Enter your name and email, then review the product and quantity before confirming. Confirmation records interest only. No payment is collected, no charge is made and no fulfillment is authorized.
Questions about PPD-12
- Are these pneumatic seals for a 12 mm shaft?
- The 12 mm dimension is the cylinder bore specified by the PPD-12 drawing, not a shaft-size claim.
- Is 7.4 mm the loose seal's inside diameter?
- No. The sheet labels 7.4 mm as the installation groove diameter. It should remain labelled that way.
- Is the seal split as shown in the picture?
- No. The picture is an explanatory cutaway. The supplied seal is continuous.
- Does the request include a cylinder repair kit?
- No. One proposed pack represents four PPD-12 seals only. Availability and final terms require separate confirmation.