Single Spring Mechanical Seal 978C — 1-1/4″ | PS-978 Equivalent

978c single spring mechanical seal, PS-978 / 978 equivalent. Fits 1-1/4″ shaft with 1.765″×.365″ seat and Type N-33 (tapered spring) rotary head.

Typical applications: Centrifugal pumps, mixers, and other rotating equipment.

Key specs: Shaft size: 1-1/4″ single spring seal • Seat: 1.765″ x 0.365″ • Rotary OD: 1.787″ • Working length: 1.062″

Design & construction:
Crimped rotary head (Type N-33)—equivalent to Pac-Seal T-21 (tapered spring) and Burgmann MG9, can replace seal type D & 2 type seal heads. Tapered spring for wide base to fit over impeller hub or other similar feature. Electro-polished 304 stainless steel metal parts. Elastomeric bellows. Non-directional (independent of shaft rotation).

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Materials available (choose from dropdown)

• CAR/CER/NIT — Carbon vs. Ceramic faces, Nitrile elastomers

• CAR/CER/VIT — Carbon vs. Ceramic faces, Viton elastomers

• SIC/SIC/VIT — Silicon Carbide vs. Silicon Carbide faces, Viton elastomers

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Have questions? Check out our Single Spring Seal Guide  or call us anytime—we’re here to help.

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Please click “specifications” below for OEM numbers and Pump Nameplate Data