These figures provide simplified information for searching, filtering and initial comparison. They are not a complete specification. Exact details depend on the model and configuration.
Power rating: Usually the motor’s rated mechanical output (P2). Electrical input power (P1) is a different value. Check the product’s nameplate or manufacturer’s documentation to confirm which rating applies.
Outlet size: The nominal size class is expressed on a millimetre basis: for example, DN40 denotes a nominal 40 mm size. It does not specify the exact measured opening, connection type, thread, flange drilling or pressure rating.
Head and flow: Indicative figures describing the pump’s performance envelope, rather than a single operating duty point. Do not assume maximum flow is available at maximum head, or that every combination within the ranges is achievable. Minimum figures do not establish safe continuous operating limits. Consult the relevant performance curve.
Check the product description, nameplate and manufacturer’s documentation before selection or installation. Please contact us before purchasing if you need help confirming suitability or connection details.
| Shipping Weight | 0.5 kg |
| Package Dimensions | 20.0 × 20.0 × 10.0 cm |
Genuine Grundfos replacement pump casing O-ring, part number 97757675. Manufactured from EPDM rubber and specified at 329.79 × 3.53mm, this seal is used on selected Grundfos end-suction and in-line pumps.
Applications include specific NB, NK, TP and TPD models, together with selected NBE, NKE, NBG, NKG, TPE, TPED and other variants listed below. This is the static casing-joint seal, commonly identified as position 72a in the applicable Grundfos service drawings.
| Manufacturer | Grundfos |
|---|---|
| Part number | 97757675 |
| Manufacturer description | Spare, O-ring |
| Application | Pump casing / cover joint on specified Grundfos pumps |
| Material | EPDM rubber |
| Nominal dimensions | 329.79mm internal diameter × 3.53mm cross-section |
| Calculated nominal outside diameter | 336.85mm, uncompressed |
| Grundfos dimension code | 329.79X3,53 |
| Service drawing position | Commonly 72a; check the drawing for the exact pump |
| Quantity supplied | One O-ring |
| Manufacturer net weight | 0.012kg |
| EAN | 5710623848082 |
| Our stock reference | #5058 |
One Grundfos 97757675 EPDM casing O-ring. A mechanical shaft seal, wear rings, additional gaskets, pump casing and other service components are not included.
329.79mm is the nominal internal diameter of the O-ring. The 3.53mm dimension is the diameter of its circular rubber cross-section. Adding twice the cross-section gives a calculated nominal outside diameter of 336.85mm. These are nominal dimensions for an uncompressed ring.
EPDM stands for ethylene propylene diene rubber. It is an elastomer commonly used for water and hot-water sealing applications. Grundfos describes ethylene propylene rubber as having excellent water resistance but very poor resistance to mineral oil and fuel. Material suitability must therefore match the pumped liquid.
On the applicable pumps, it seals the stationary joint between the pump housing and its cover or motor-stool assembly. Grundfos commonly identifies this casing seal as position 72a. The exact assembly arrangement must be checked against the service drawing for your pump.
No. The casing O-ring seals a stationary housing joint. The mechanical shaft seal seals around the rotating shaft and is a separate component. Replacing this O-ring will not repair a worn mechanical shaft seal.
No. These pump families use several casing sizes and seal materials. Match 97757675 against the service parts information for the complete eight-digit pump product number, taking account of its production code and configuration. Family name or flange size alone is insufficient.
Those codes form part of the complete pump designation and describe its mechanical shaft-seal arrangement. They help identify the pump, but they do not independently establish the size of its casing O-ring. The references below were checked for the exact casing O-ring part number 97757675.
Do not select an alternative by dimensions alone. For this size, the Grundfos NB/NBE Range 6 catalogue distinguishes 97757675 — EPDM, 97757705 — FKM/Viton and 92526503 — EPDM-NSF. These are separate specifications. This listing is for standard EPDM part 97757675; it does not claim the certification of the separately listed EPDM-NSF version.
EPDM is commonly selected for water-based systems, including suitable heating and cooling applications. For glycol mixtures, confirm compatibility with the actual glycol type, concentration, inhibitors and operating temperature. The pump manufacturer's requirements and the fluid supplier's compatibility guidance should both be followed.
The O-ring's material and dimensions do not establish a universal operating limit for every pump. Use the permitted temperature and pressure limits for the exact pump, liquid and seal configuration. General EPDM temperature information should not be treated as an operating rating for the assembled pump.
This listing supplies one O-ring. The quantity required depends on which pump-head joints are being opened and the relevant service drawing. If both heads are being serviced, check the parts quantities before ordering.
Grundfos service instructions call for replacement of gaskets and O-rings during servicing. A used ring may have taken a compression set or suffered damage during removal, even when it appears intact.
Isolate, depressurise and drain the pump, allowing hot equipment to cool before dismantling. Clean and inspect the seal groove and mating surfaces, fit the ring without twisting or pinching it, and use the lubricant and tightening procedure specified for the exact pump. Avoid assuming that a general-purpose oil or grease is compatible with EPDM.
It can address leakage from the casing joint where this ring is the specified seal and the sealing surfaces remain serviceable. Leakage from the shaft seal, plugs, pipe flanges or a damaged casting requires separate diagnosis.
Send us a clear photograph of the pump nameplate, including its complete product number and production code, together with the existing spare-part label if available.
The Pump Dealer
Telephone: 01803 220416
Email: kirk@thepumpdealer.co.uk
Please quote 97757675 / stock #5058.
Our research identified 596 manufacturer pump references whose recommended service-parts records include 97757675. The list below contains 578 published model designations, followed by 16 abbreviated manufacturer descriptions and two service-special references.
The eight-digit number at the end of each entry identifies the pump. Full published type codes have been retained where available, including separate product numbers sharing the same model description.
Grundfos publishes abbreviated model names for the following references. Their separate technical records confirm the shaft-seal codes shown in brackets, and their recommended-parts records include 97757675. Missing full type-code suffixes have not been inferred.
The following manufacturer service-special records also list 97757675. Their public records do not publish a complete model designation, so identification must be by the exact product number.
Compatibility research checked against Grundfos manufacturer records on 21 October 2026. Every pump product number listed above was checked for the exact replacement part 97757675. Confirm suitability for the individual pump and application before fitting.
Specification & guidance notice: Technical information and FAQ content are provided in good faith based on manufacturer literature and industry experience. Descriptions of hydraulic types and application suitability represent general guidance only and do not constitute a guarantee of performance. Actual results will depend on system design, pipework losses, media characteristics, and installation conditions. Please consult the manufacturer & thier documentation and satisfy yourself that the equipment is suitable for your specific application prior to purchase.