3″ CH&E Replacement Diaphragm – TPE

The CH&E 3 Inch TPE Replacement Diaphragm P2726TPE is the thermoplastic version of the diaphragm for CH&E 5500 and 6500 series pumps. The CH&E parts manual lists P2726 as item 15 for both the 5500 aluminum and 6500 cast iron build. The part also appears in US federal stock records under NSN 1730-00-133-4766. Your pump uses one. Check your model and serial number before ordering. Ken’s Distributing can quote single replacements, quantity orders, and repeat-supply requirements. Include the pump model, serial number, required quantity, and NSN or purchase-order information in your request.

Product Highlights

• Part number P2726TPE. Base number P2726, item 15 in the CH&E 3 inch parts list.
• Listed in US federal stock records under NSN 1730-00-133-4766.
• Fits CH&E 5500 series aluminum and 6500 series cast iron 3 inch pumps.
• TPE is one of five compounds CH&E lists, alongside rubber, neoprene, Buna-N and Viton.
• One diaphragm per pump.
• Matching TPE rebuild kit is W103-030.0T.
• Bulk pricing from 15 units. Blanket orders available for fleets and multi-crew operations.

Specification Table

About the CH&E 3 Inch TPE Replacement Diaphragm

This is the flexing part that drives water through the pump. It sits between the pump frame and the water box. When it splits or leaks, the pump stops priming, loses stroke, or stops moving water.

The CH&E parts manual lists this part as item 15, number P2726, for 3″ gas engine powered pumps. The TPE version is P2726TPE. Your pump uses one.

TPE stands for thermoplastic elastomer. It is one of five compounds CH&E lists for this part, along with rubber, neoprene, Buna-N and Viton. All five share the same shape and the same mounting.

Ordering by NSN

This part is in the US federal supply system. Its National Stock Number is 1730-00-133-4766, listed as a pumping unit diaphragm, with P2726 and P2726TPE as the reference numbers.

Buyers using government, municipal, utility, fleet, or institutional purchasing systems may encounter the NSN instead of the manufacturer reference. Your requisition system may show you the NSN and nothing else. If that is all you have, send it to us and we will match it to the part.

We can also quote against a purchase order and set up repeat supply. Blanket orders are available for fleets and multi-crew operations.

What we can and cannot tell you about TPE

We can tell you exactly what the part is. P2726TPE is a documented number in federal stock records, not a catalogue guess.

We cannot give you a temperature rating, a chemical compatibility list, or a service life figure. CH&E does not publish them.

You will see sellers claim TPE lasts twice as long as rubber, or that it holds up where other compounds fail. We used to say something like that on this page. We have taken it down, because we cannot show you the data behind it.

What we can do is help you reason it through. Tell us what you pump, how hot the job runs, and how your last diaphragm failed. If your fluid is genuinely aggressive, ask us about Viton, part P2726V. It sits above TPE in the CH&E range.

Which pumps this diaphragm fits

The CH&E manual lists P2726 for these 3 inch gas engine powered pumps:

• CH&E 5500 series, aluminum
• CH&E 6500 series, cast iron

The manual uses the same number for both. They differ in the metal used for the wetted parts, not in the diaphragm. Model numbers across this line run from 5500 to 6535.

CH&E built other 3 inch diaphragm pumps outside these series. We have not confirmed this part for those. If your model does not start with 55 or 65, contact us first.

Fitting the diaphragm

The CH&E manual gives these steps for 3 inch pumps.

Turn the connecting rod to the down position. Take out the four bolts that clamp the diaphragm between the pump frame and the water box. Take off the three nuts holding the diaphragm to the diaphragm bottom plate.

Fit the new diaphragm onto the studs and the bottom plate. Use a pipe spacer over the studs to seat it. Put the assembly back on the connecting rod.

Tighten the three nuts to 45 to 54 N-m, which is 35 to 40 lb-ft. Center the diaphragm over the water box. Clamp it with the four bolts in a crossing pattern at the same torque. The torque is the same whichever compound you fit, but the 2 inch pumps use a lower setting.

Parts to check while the pump is open

• Flap valve assembly. There is no TPE version. The 3 inch options are Buna-N SA10001B, neoprene SA-10001N, Viton SA-10001V, and SA-10002N in neoprene with a cloth insert
• Diaphragm bottom plate, P3306
• Retaining washers, P3317, two per pump
• Connecting rod, P3305

If more than one is worn, the TPE rebuild kit W103-030.0T may cost less than buying parts one at a time. For fleets, ask us about stocking kits rather than single parts.

Get a quote or set up repeat supply

Send us your pump model number, your serial number, and how many you need. If you are ordering against an NSN or a purchase order, send that instead and we will match it.

Frequently Asked Questions

What pumps does part number P2726TPE fit?

P2726TPE is the TPE version of the diaphragm listed in the CH&E parts manual for 3 inch gas engine powered pumps in the 5500 aluminum series and the 6500 cast iron series. One base number, P2726, covers both builds, and the model range runs from 5500 to 6535. CH&E built other 3 inch pumps outside these series and we have not confirmed this part for those. Check your nameplate before ordering.

What is NSN 1730-00-133-4766?

It is the National Stock Number for this diaphragm in the US federal supply system. The record lists it as a pumping unit diaphragm and gives P2726 and P2726TPE as the reference numbers. If you buy through a government, military or municipal system, the NSN may be the only identifier you see. The NSN provides an additional catalogued identifier that can be used alongside P2726 and P2726TPE during part verification. You can request a quote using the NSN, the manufacturer reference, or both.

I have an NSN but not a part number. How do I order?

Send us the NSN and we will match it. For this diaphragm the NSN is 1730-00-133-4766 and the part number is P2726TPE. If your requisition shows a different NSN, send that too, because a nearby number may point to the 2 inch diaphragm or to a different compound. Add your pump model and serial number if you have them. We will confirm the part before we quote so nothing gets ordered twice.

Will TPE double the life of a rubber diaphragm?

We cannot tell you that, and we no longer say it. This page used to. CH&E does not publish service life figures, temperature ratings or chemical compatibility data for any of its diaphragm compounds. What we can do is help you reason it out. Tell us what you pump, how hot the job runs, and how your last diaphragm failed, and we will give you our best view.

What flap valve goes with a TPE diaphragm on a 3 inch pump?

There is no TPE flap valve. CH&E lists four for the 3″ pump and none is TPE. The options are SA-10001B in Buna-N, SA-10001N in neoprene, SA-10001V in Viton, and SA-10002N in neoprene with a cloth insert. The parts list shows SA-10001N as standard fitment. The flap valve sits in the same fluid as the diaphragm, so call us and we will help you choose one.

Can I order these in quantity?

Quantity pricing and scheduled-supply arrangements may be available. Include the required quantity, delivery schedule, and account information in the quote request.We set up blanket orders for fleets, rental yards and multi-crew operations. Each pump takes one diaphragm, so count your pumps and add spares based on how hard they run. If you also want flap valves and bottom plates, the TPE rebuild kit W103-030.0T bundles the wear parts. Send us your pump list and we will put together a stocking plan.

Which pumps besides CH&E use P2726?

Multiquip catalogues list P2726 as a diaphragm for the Polyquip pump, using the same number. That is a catalogue match rather than a measured swap, so we do not call it confirmed. A Magnum Products manual for models MCP5537 and MCP6537 also uses the same 5500 to 6500 parts drawings, and Mud Hog models MCP 5515, MCP 5537 and MCP 5538 are linked to this line. Send us your model and serial number and we will check before you order.

What torque should I use when I fit this diaphragm?

The CH&E manual gives 45 to 54 N-m for 3 inch pumps, which is 35 to 40 lb-ft. Use it twice. First on the three nuts holding the diaphragm to the diaphragm bottom plate. Then on the four bolts clamping the diaphragm between the pump frame and the water box. Tighten those four in a crossing pattern so the clamp is even. The 2 inch pumps use a lower setting, so check your pump size first.