Sealing Sleeve 20mm

The hard 20 mm cup seal with dimensions 20×28×5.3/3 is a sealing element used in the working section of high-pressure pumps. It maintains tightness in the pump’s operating area, which supports stable working pressure and reduces water leakage.

MPN / reference: 40023
Dimensions / size: 20×28×5.3/3
Weight: 0.001 kg

APPLICATION

Cup seal used in service work for pumps and pressure washers, including:

• replacing the seal in the piston section / pump head,
• pump refurbishment after prolonged use or when performance drops,
• eliminating leaks around the pump section,
• periodic high-pressure system service (replacement of sealing parts).

SYMPTOMS - WHEN IT’S WORTH REPLACING

Signs of cup seal wear or damage:

• water leaks around the pump or under the housing,
• drop in working pressure despite a correctly selected nozzle,
• jet pulsation and pressure fluctuations during operation,
• moisture on pump components after downtime (leaks show up “later”),
• visible damage/chipping of the seal after disassembly.

HOW TO CHOOSE THE RIGHT PART

Selection must be precise - profile and working height differences affect tightness:

• by dimensions: 20×28×5.3/3 (inner diameter, outer diameter, and height/profile),
• by manufacturer MPN / reference: 40023,
• by comparison with the removed part: check working profile and dimensions before installation.

If the part is selected for a pump overhaul, also inspect cooperating components (plunger condition, guides), because mechanical wear can affect the life of the new cup seal.

COMPATIBILITY

Compatibility should be determined based on MPN 40023 and the 20×28×5.3/3 size according to pump documentation or the parts table.
Selecting only by the general “20 mm” description without verifying full dimensions and profile is not recommended.

[faq]

Will the 20×28×5.3/3 cup seal fit every “20 mm” pump?|Not necessarily. “20 mm” does not always mean the same seal profile. Fit depends on full dimensions and working shape, so it’s best to select by MPN 40023 or by comparing with the removed part.
What does 5.3/3 mean in the cup seal dimension?|It indicates the element height/profile. In service practice, even a small profile difference can cause leaks or rapid wear, so the seal must be selected exactly according to specification.
Can I use an aftermarket cup seal?|Yes, but only if the alternative has identical dimensions and profile and is rated for high-pressure systems. Incorrect selection usually results in leaks and reduced performance, so the MPN and pump technical data should be your reference point.

[/faq]