3″ CH&E Replacement Diaphragm – Neoprene
The CH&E 3 Inch Neoprene Replacement Diaphragm P2726N is the flexing part that drives water through your 3 inch pump. The CH&E parts manual lists P2726 as item 15 for the 5500 aluminum and 6500 cast iron pumps. Multiquip also carries this same number for the Polyquip pump. Your pump uses one. Check the model and serial number on your nameplate before you order, and compare your old part. Ken’s Distributing will review fitment with you if you are unsure.
Key Product Highlights
- Manufacturer part number P2726, item 15 in the CH&E 3″ parts list. Neoprene variant P2726N.
- Fits CH&E 5500 series aluminum and 6500 series cast iron 3 inch pumps.
- Multiquip lists the same number, P2726, for the Polyquip pump.
- Neoprene compound. Also made in rubber, Buna-N, TPE and Viton.
- One diaphragm per pump.
- Matching neoprene rebuild kit is W103-030.0N.
- Check your pump model and serial number before ordering.
Specification Table
| Field | Value |
|---|---|
| Product type | Replacement diaphragm |
| Pump brand | CH&E |
| Manufacturer | C. H. & E. Manufacturing Co. Inc. |
| Manufacturer part number | P2726 |
| Material-specific part number | P2726N, neoprene |
| Cross-reference number | P2726, listed by Multiquip for the Polyquip pump |
| Nominal pump size | 3″ |
| Diaphragm material | Neoprene |
| Verified pump models | CH&E 5500 series aluminum, CH&E 6500 series cast iron, 3 inch gas engine powered |
| Model range | 5500 to 6535. Confirm before ordering |
| Mounting design | Clamped by four bolts between the pump frame and water box. Held by three nuts on studs at the diaphragm bottom plate |
| Installation torque | 45 to 54 N-m, 35 to 40 lb-ft, on 3″ pumps |
| Quantity per pump | 1 |
| Matching rebuild kit | W103-030.0N, neoprene, 3 inch |
| Matching flap valve | SA-10001N, neoprene |
| Fitment requirement | Confirm pump model and serial number before ordering |
Check this fits your pump
Do these four things before you order.
- Find the nameplate on your pump. Write down the model number and the serial number. The CH&E manual asks you to record both before ordering any part.
- Check that your pump is a 3 inch. The 3 inch is the port size where the hose connects. It is not the width of the diaphragm.
- Pull your old diaphragm. Measure the outside diameter and the thickness. Count the holes.
- Look for a number stamped on the old part. Compare it to P2726.
If all four details match, the diaphragm is likely to be correct. Contact Ken’s Distributing if any fitment detail remains uncertain.
Do not order by how the part looks. Two diaphragms can look alike and fit different pumps.
About the CH&E 3 Inch Neoprene Replacement Diaphragm
This is the flexing part that moves 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 inch gas engine powered pumps. Your pump uses one.
Neoprene is one of five compounds CH&E lists for this part. The others are rubber, Buna-N, TPE and Viton. Pick the compound that matches what you pump.
Part number P2726 and its cross-references
The same P2726 reference appears in CH&E and Multiquip documentation.
| Number | Listed as | Source |
|---|---|---|
| P2726 | Diaphragm, item 15, 3 inch pumps | CH&E parts manual for 5500 and 6500 series |
| P2726N | Neoprene version | CH&E material suffix. N is neoprene |
| P2726B, P2726R, P2726TPE, P2726V | Buna-N, rubber, TPE and Viton versions | Same base part in other compounds |
| P2726 | Diaphragm, Polyquip Pump | Multiquip parts catalogues |
The Multiquip listing matters if you bought your part from an equipment dealer rather than a pump dealer. You may have paperwork that calls it a Polyquip diaphragm. It carries the same number.
We list this as a catalogue match, not a promise. We have not measured a Multiquip part against a CH&E part. If your paperwork shows P2726 from another supplier, send us the number and your pump model and we will check it.
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 part number for both. The 5500 and the 6500 differ in the metal used for the wetted parts, not in the diaphragm.
Model numbers across this line run from 5500 to 6535. Confirm your exact model before ordering.
Magnum and Mud Hog 3 inch pumps are related to this line. A Magnum Products manual for models MCP5537 and MCP6537 uses the same 5500 to 6500 parts drawings. Model numbers we have seen linked to this line include MCP 5515, MCP 5537 and MCP 5538. We have not confirmed the diaphragm line item in the Magnum manual, so we do not list those pumps as verified here. If you run a Magnum or a Mud Hog, contact us with your model and serial number.
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.
Note that the 3 inch torque is higher than the 2 inch figure. Do not use 2 inch settings on a 3 inch pump.
Parts to check while the pump is open
These parts sit next to the diaphragm and wear at a similar rate.
- Flap valve assembly, SA-10001N in neoprene. SA-10002N is the neoprene version with a cloth insert
- Diaphragm bottom plate, P3306
- Retaining washers, P3317, two per pump
- Connecting rod, P3305
If more than one is worn, the neoprene rebuild kit W103-030.0N may cost less than buying parts one at a time.
Need help with fitment
Send us your pump model number, your serial number, and any number stamped on your old diaphragm. Ken’s Distributing will check it against the CH&E parts list and tell you what you need. Call (303) 699-7845 or email us.
Frequently Asked Questions
What pumps does part number P2726 fit?
P2726 is listed in the CH&E parts manual as the diaphragm for 3 inch gas engine powered pumps in the 5500 aluminum series and the 6500 cast iron series. The manual uses the same number for both builds. Model numbers across this line run from 5500 to 6535. Other pumps may take a different part. Check the model and serial number on your pump nameplate before you order. If your pump is not in this range, contact us and we will look it up for you.
Is the Multiquip P2726 the same part as this one?
Multiquip catalogues list P2726 as a diaphragm for the Polyquip pump, using the same number CH&E uses. That is a catalogue match, and it is a strong sign the two are the same item. We have not measured a Multiquip part against a CH&E part, so we cannot call it a confirmed swap. If your paperwork calls the part a Polyquip diaphragm, send us the number and your pump model. We will check it before you buy.
Does P2726 fit a Magnum or Mud Hog 3 inch pump?
It may, but we do not list those pumps as verified. A Magnum Products manual covers models MCP5537 and MCP6537 and uses the same 5500 to 6500 parts drawings as the CH&E manual. Model numbers linked to this line include MCP 5515, MCP 5537 and MCP 5538. We have not read the diaphragm line item in that manual ourselves. Contact us with your Magnum or Mud Hog model and serial number and we will confirm it before you order.
What is the difference between the CH&E 5500 and the 6500?
The 5500 is the aluminum build and the 6500 is the cast iron build. The difference is in the metal used for the wetted parts, such as the water box and the suction connection. It is not a difference in the diaphragm. The CH&E parts manual lists the same diaphragm number, P2726, in both the 5500 column and the 6500 column. So this part suits either one. You still need to check your model and serial number.
Is the 3 inch measurement the size of the diaphragm?
No. The 3 inch is the port size on the pump, which is where the hose connects. The diaphragm itself is much wider than 3 inches. This is the most common ordering mistake we see. Do not measure your old diaphragm and then look for a part with that number of inches in the name. Match your pump model first. Then compare your old part against the listed part number, and measure to double check.
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 that hold the diaphragm to the diaphragm bottom plate. Then on the four bolts that clamp the diaphragm between the pump frame and the water box. Tighten those four in a crossing pattern so the clamp is even. The 3 inch figure is higher than the 2 inch figure, so check which pump you have.
What does the N mean in P2726N?
The letter at the end shows the compound. N means neoprene. CH&E uses one base number with different letters for different materials. You will see B for Buna-N, R for rubber, V for Viton and TPE for the TPE version. So P2726N and P2726R are the same shape of part in two compounds. Older paperwork may show just P2726 with no letter. Pick the compound that suits what you pump, and ask us if you are not sure.
Which other parts should I check while the pump is open?
Check the flap valve assembly, SA-10001N in neoprene, or SA-10002N if yours has a cloth insert. Also look at the diaphragm bottom plate P3306, the two retaining washers P3317, and the connecting rod P3305. These sit right next to the diaphragm and wear at a similar rate. If more than one is worn, the neoprene rebuild kit W103-030.0N may cost less than single parts. Ask us and we will tell you which suits your pump.