Sealless Canned-Motor Process Pumps

A pump and motor configuration, not a seal-plan substitution

A canned-motor process-pump inquiry needs to define the hydraulic unit, motor, liquid circulation and supporting protection as a package. It is not simply an instruction to remove the shaft seal from an existing process pump. The distinction also matters when buying bearings, wear components or a complete replacement.

HERMETIC's CNP/CNPF/CNPK product information describes the family as a sealless pump design according to API 685. That is the manufacturer's design statement, not proof that an offered assembly has been certified or that an API 610 selection can be substituted unchanged.

Read the catalogue example literally

The same document uses CNP 100 x 80 x 200 B1 as a denomination example: nominal suction diameter 100 mm, nominal discharge diameter 80 mm, and nominal impeller diameter 200 mm. These are naming fields, not a pump curve, a certified installation drawing or the final trimmed impeller diameter.

The CN/CNF V-Line catalogue provides actual hydraulic/motor rows, not just a denomination example. Its page 20 lists 65-40-160 + N34L-2 with DN (N1) 65, DN (N2) 40 and an approximate total weight of 140 kg. N1 and N2 are separate connections identified in the drawing on page 19. DN is a nominal connection designation, not a measured internal bore in millimetres.

The same hydraulic size with N34XL-2, rather than N34L-2, is listed at approximately 200 kg. Keep the motor suffix attached to the quoted combination; do not transfer one row's weight to the other. These are catalogue approximate weights, not shipping gross weights or lifting-design values.

The catalogue separately identifies EN 22858 / ISO 2858 as the housing connection-dimension reference. That statement does not turn the CN/CNF example into an API 685-certified assembly. The CNP design reference and this CN/CNF configuration remain separate.

Compare circulation arrangements, not brand initials

TEIKOKU's F/FA description distinguishes configurations with and without a connecting body and identifies particle-free, low-to-medium-temperature liquid service. Its B-type description instead describes auxiliary-impeller circulation, an external heat exchanger and a thermal barrier.

These examples show why cooling and circulation questions belong in the RFQ. They are not a cross-brand equivalence table. Ask the bidder to identify the selected liquid path, utility requirements, materials and monitoring scope for the stated process conditions.

Keep a spare-parts line separate from a complete pump

The HERMETIC CNP catalogue lists wear rings, bearing sleeves, bearing bushes and slide rings. Its reduced parts list describes component categories; it does not supply a universal replacement code for every pump size.

The manufacturer's spare-parts page asks for item or part numbers, quantities and the HERMETIC serial number. Include the installed assembly identity and relevant drawing with an inquiry. A similarly named bearing or wear ring from another series is not automatically interchangeable.

RFQ and acceptance scope

Provide the fluid composition, temperature, viscosity and solids information, required flow/head duty, suction conditions, electrical supply and applicable location requirements. Request a selected curve and an explicit boundary for the motor, cooling, instrumentation, protection and site work.

Use the process-pump reference to keep a different pump construction identifiable in the bid comparison. Send complete pumps and spare parts as separate RFQ lines. Current drawings, agreed tests and any required configuration-specific certificates are quotation and acceptance documents; the public examples establish neither stock, authorization nor suitability for a particular liquid.

Work through the circulation arrangement and serial-number checks for a canned-motor pump in Canned-Motor Pumps: Circulation Selection and Serial-Matched Parts.