A Chevron Packing seal, also known as V‑packing, Vee packing or stem packing, is a robust multi‑lip sealing system used in high‑pressure hydraulic and pneumatic applications, especially for reciprocating pistons, rods in hydraulic cylinders, valve stems, downhole tools and oil & gas equipment to prevent fluid leakage. It consists of multiple V‑shaped rings stacked between male and female adapters. Typically made from durable elastomers such as NBR, HNBR, FKM and FFKM, along with high‑performance engineering plastics like PTFE and PEEK, these seals deliver reliable performance in demanding industries such as oil & gas, mining and heavy machinery.

Chevron Packing seals are built around a modular, multi‑element structure that gives them high‑pressure capability and long‑term reliability. The core design consists of several distinct components working together as a single sealing set rather than a monolithic ring.

Main sealing elements – V‑rings

The heart of the assembly is a stack of V‑shaped rings (V‑rings), typically made from elastomers such as NBR, HNBR, FKM or FFKM or from high‑performance plastics like PTFE or PEEK. Each V‑ring contributes to one or more sealing lips, so the overall set forms a multi‑lip barrier that effectively contains fluid or gas along the shaft or piston.

Pressure ring (female adapter / top ring)

At the loaded end of the stack sits a pressure ring, also called a female adapter or top ring. This part helps distribute the compressive load evenly across the V‑rings, guides the stack into the gland and provides initial sealing contact before full system pressure is applied.

Support ring (male adapter / bottom ring)

At the opposite end is a support ring, often referred to as a male adapter or bottom ring. This ring anchors the assembly, maintains axial preload and helps prevent extrusion of the softer V‑rings under high pressure, especially in dynamic rod or piston applications.

Chevron Packing seals use a stack of V‑shaped rings that form a dynamic, self‑tightening seal along the rod or piston. During installation, the set is compressed between a male adapter (bottom ring) and a female adapter (top ring) inside the gland, creating light contact between the V‑ring lips and the sealing surfaces. This provides a basic barrier against leakage even at low or zero pressure.

When hydraulic or pneumatic pressure is applied, it acts on the open side of the V‑rings, pushing the arms of the “V” outward toward the rod and the gland wall. This pressure assisted action increases the contact force of the lips, so the seal becomes tighter as pressure rises, instead of relying only on the initial mechanical compression. Each ring in the stack shares part of the load, with upstream rings facing higher pressure and downstream rings seeing less, which spreads the sealing force along the length and reduces stress concentration on any single ring.

The V‑shaped cross‑section also allows each ring to flex and pivot slightly at the hinge of the V. This flexibility helps the seal follow small misalignments, rod run‑out, vibration and reciprocating motion, maintaining continuous contact without cracking or tearing. Friction between the moving rod and the softer V‑rings produces heat and gradual wear, but pressure continues to push the remaining material outward, shifting the contact area and closing gaps, so leakage control is maintained over many cycles.

The male adapter anchors the stack and prevents the rings from being pushed down the gland, while the female adapter transmits the compressive load evenly and controls how much the set is compressed. Together, the adapters keep the V‑ring stack in the correct position, protect the softer rings from being squeezed into the clearance gap and help the seal deliver consistent, durable performance in high‑pressure hydraulic and pneumatic service.

➤ Engineered for high‑pressure, high‑temperature service in oil & gas, downhole tools, hydraulic cylinders and heavy industrial equipment.

➤ Multi‑lip V‑ring design that self‑energizes under system pressure, providing tight, low‑leak sealing in dynamic and reciprocating applications.

➤ Manufactured from high‑performance elastomers (NBR, HNBR, FKM, FFKM) and advanced engineering plastics (PTFE, PEEK) from the ISMAT Vertex and Novum material series

➤ Excellent resistance to wear, extrusion, chemicals and aggressive media, even in harsh and contaminated environments.

➤ Flexible V‑ring geometry that tolerates misalignment, rod run‑out and vibration while maintaining continuous sealing contact.

➤ Customizable configurations tailored to specific pressure, temperature and media requirements for each application.

➤ Modular stack design for easier inspection, adjustment and replacement of rings, helping to reduce downtime and extend service life.

➤ Backed by ISMAT’s technical expertise, precision compounding and quality control to deliver reliable, production‑ready Chevron Packing Seals for critical sealing duties.