Valve Ball 5,5mm

The 5.5 mm pump ball is a small valve element used in pressure-washer pump subassemblies, working as part of a check/shut-off function in a valve seat. Its condition directly affects seat tightness, the ability to hold pressure, and overall pump stability. In service, it’s replaced during valve overhauls, after damage, or when leakage symptoms appear in the pump section.

MPN / reference: 13238
Ball diameter: 5.5 mm

APPLICATION

The ball is used in typical pump service work:

• rebuilding valve elements and seats in the pump,
• replacing the ball in a check-valve circuit during overhaul,
• restoring valve-seat tightness after wear or contamination,
• servicing pumps used in workshop/industrial conditions where contamination accelerates valve wear.

SYMPTOMS - WHEN IT’S WORTH REPLACING

Consider replacing the ball when you notice:

• problems holding pressure or fluctuations in operating parameters,
• unstable pump operation (valve “leak-through” symptoms),
• recurring performance drops after ruling out accessories (nozzle, hose),
• visible wear after removal (pitting, deformation, dulling),
• contamination or valve-seat damage indicating operation on dirty water.

HOW TO CHOOSE THE RIGHT PART

Selection should be unambiguous:

• verify the 5.5 mm diameter,
• confirm the manufacturer number: MPN 13238,
• compare with the removed part (diameter and seat fit),
• check the seat condition - a worn seat can leak even with a new ball.

For valve components, precision is critical-differences of tenths of a millimeter can change sealing and shut-off behavior.

COMPATIBILITY

Select the ball based on MPN 13238 and the 5.5 mm diameter, according to the pump subassembly service documentation. Don’t choose “by diameter only” without confirming the part number and seat compatibility.

[faq]

Is the 5.5 mm ball a single-use part at every valve overhaul?|Not always, but if it shows wear or has run on contaminated water, replacement is the safest option. It’s a small part, and leakage here can destabilize the entire pump.

How can I recognize a worn ball after removal?|Look for pitting, dulling, a “contact spot” from the seat, deformation, or surface damage. Even small defects can cause leak-through at the seat.

Is replacing the ball alone enough if the seat is worn?|Often not. If the seat has pitting or is uneven, a new ball won’t seal properly. In service, the pair is assessed: ball + seat.

Can contamination in the water cause symptoms similar to a worn ball?|Yes. Sand and deposits can enter the seat and prevent proper closing. That’s why inlet filtration and water cleanliness should always be checked with valve issues.

What should I check after reassembling the system with a new ball?|Pressure stability under load, no parameter fluctuations, and proper valve sealing (no “leak-through” symptoms). If the issue returns, the seat or other valve components are usually the next suspects.

[/faq]