USS / CSS / HSS · Combined-duty review
Spring-energized PTFE / UHMWPE seal family
QuanSeaL combines polymer seal bodies with different spring constructions. The official style rows contain distinct temperature and surface-speed guidance; none is a universal rating for every seal or application.
Keep each style’s guidance together
| Style / spring | Temperature | Shaft surface velocity | Listed load behaviour |
|---|---|---|---|
| USS / U | −100 °F to 600 °F | <300 sfpm | Medium load with deflection |
| CSS / C | −100 °F to 450 °F | <300 sfpm | Uniform load with deflection |
| HSS / H | −360 °F to 600 °F | <10 sfpm | High load with deflection |
The pressure row for all three lists general vacuum to 3,000 psi standard, with special constructions up to 10,000 psi. The page separately advertises 250 °C, 100 MPa and 5 m/s in broad prose. [1] These are different presentations, not evidence a selected seal can operate at all the maxima simultaneously.
The speed heading describes shaft surface velocity, not rpm. HSS is described for static/vacuum contexts; do not apply USS/CSS speed guidance to it. No numeric limit is assigned in structured data to an unspecified configuration.
Similar style names do not specify the same gland
The actual page distinguishes profile variants such as LWL-R/LWL-P and SWL-R/SWC-P: O-ring position, corner/chamfer and spring form differ. It repeats SWC-P in two entries. [1] Request the controlled selected drawing rather than deriving geometry from that repeated label.
- Body
- Exact polymer compound/formulation and profile, not “PTFE” or “UHMWPE” alone.
- Spring
- Selected construction, material and load/deflection basis for the duty.
- Gland and interfaces
- Shaft/bore dimensions, groove width/depth, tolerances, clearances and mating surfaces.
- Assembly
- Open/closed gland constraints, orientation and supplier’s controlled installation instructions.
A matching outside diameter does not define lip geometry, gland fit or friction. Nor does a spring-style label determine compatibility with the actual fluid or contaminants.
Describe pressure, temperature and motion as one duty
Rotary
Provide shaft diameter/speed, pressure, temperature, media/lubrication and surface condition together. Ask for the supported envelope and applicable validation.
Reciprocating or static
Provide stroke/cycle or static/vacuum objective, pressure direction, start-up/transient conditions and installed geometry.
Parker’s own PTFE guide explains that rotary pressure and velocity interact with frictional heat, and spring load affects friction/wear. [2] That engineering context supports a combined selection question. It does not authorize transferring Parker curves, life claims or interchangeability to a QuanSeaL seal.
Can the catalogue’s lowest temperature and highest speed be combined?
No combined approval is established. Obtain one exact construction and its supported duty, including relevant media, lubrication and geometry. Do not merge values from different style rows or broad family prose.
Make the acceptance measurable
- Record the selection. Full profile/size, compound, spring material, controlled gland/seal drawings and permitted conditions.
- Agree the objective. Relevant leakage, friction, functional or endurance acceptance under defined representative conditions.
- Record the actual trial. Sample identity, fixture/mating surfaces, media, pressure/temperature/motion, results and limitations.
- Control repeat supply. Preserve material/geometry identity, agreed lot evidence and approval for changes.
This is a proposed validation agreement, not a platform test or promised leak-free/service-life outcome. A supplier statement that PTFE resists corrosion cannot approve every filled compound, spring or media combination.
Request one supported construction
Sources & review
- Official spring-seal style and profile page ↗
Actual style rows, original °F/sfpm/psi units and profile/O-ring differences; headline maxima not a selected construction’s simultaneous rating.
2026-10-11 - Parker PTFE guide, section 3.6 ↗
Primary engineering discussion of combined rotary pressure/velocity/temperature and spring load; its product ratings are not QuanSeaL ratings.
2026-10-11
Specifications come from the manufacturer’s published information and the sources above; buying advice is written by CivilEquip with AI assistance. Ask the manufacturer to confirm the data for your configuration. Editorial policy · Report a correction.