Tapflo CTS-I Self-Priming Industrial Centrifugal Pump

A self-priming stainless steel centrifugal pump with 4.5 m suction lift

The CTS-I is the industrial self-priming version of the Tapflo CT range: an open-impeller centrifugal pump made from AISI 316L that can create up to 4.5 m of suction lift. A priming chamber in front of the casing keeps liquid for re-priming, so the pump can empty tanks, sumps and drums from above and cope with highly aerated liquids. It retains the simple design of the standard CT pumps and is offered in sizes C, D and E for chemical, oil and gas, mining, printing, automotive and wastewater duties.

Technical specifications

How self-priming works

The casing must be filled with liquid above the impeller before start-up. When the pump starts it draws air from the suction line, creating negative pressure that lifts the product; air mixes with liquid in the casing and escapes through the discharge line while liquid returns to the impeller. This repeats until the suction line is free of air and the pump behaves as a standard centrifugal pump. The discharge shut-off or regulation valve therefore has to be open during priming, which is the main installation rule for this series.

Seal options and dry-run protection

Tapflo offers an oil-lubricated mechanical seal, a buffer fluid system for products that solidify or crystallise, and a quench option that is recommended when there is a risk of dry running, because circulating quench liquid also carries heat away from the seal. The CTS-I and its hygienic sibling CTS-H share the brochure; the I version has glass-blasted surfaces and BSPT threads rather than polished surfaces and DIN 11851 couplings.

Where the Tapflo CTS-I is used

• Emptying tanks, sumps and drums from above
• Transfer of chemicals and solvents in process plants
• Oil and gas and mining duties
• Printing and automotive production lines
• Wastewater and effluent handling
• Liquids that carry air or gas bubbles

Selection checklist for the Tapflo CTS-I

• Pump size, C, D or E, and the model on the 2900 rpm curve
• Suction lift needed, up to 4.5 m
• Flow and head, read from the performance curve
• Liquid temperature, up to 90 degrees C, and viscosity up to about 200 cSt
• Particle size, up to 6 mm with the open impeller
• Seal type and O-ring material for the liquid
• Motor to IEC standard, 3-phase, 2-pole, IP55
• Flange standard, EN 1092-1 or ANSI 150 lbs

Installation, commissioning and maintenance notes

Fill the casing with liquid before the first start, and again after any long stop. Keep the suction line short, straight and tight, since an air leak will stop the priming. Open the discharge valve during priming so that the air can leave. Do not run the pump dry for long periods. Check the seal for leakage and the impeller for wear at regular intervals, and keep the drain plug accessible.

Requesting a quotation for the Tapflo CTS-I

Please send the liquid, the temperature, the flow, the head and the suction lift. Seven Star LLC serves industrial customers in Oman and the GCC and replies with a quotation based on the information provided.

CTS-I seal choices

The standard seal is ceramic against graphite. Silicon carbide pairs and an oil-lubricated seal are options. O-rings are EPDM as standard, or FKM, FEP/silicone or NBR.

CTS-I pressure rating

Size C is rated PN 2.5 and sizes D and E are rated PN 4, at 20 degrees C.

CTS-I connections

Size C has a 1 1/2 inch inlet and outlet. Sizes D and E have a 2 1/2 inch inlet and a 2 inch outlet. All sizes have a 3/8 inch drain.

CTS-I impeller

The impeller is AISI 316L and is open as standard. A semi-open impeller is available.

Pump records for CTS-I

Keep the model, the seal type and the date of the last seal change with the pump list.

Choosing the right Tapflo CTS-I size

Start from the flow and the head at the duty point, then read the performance curve of each model at 2900 rpm. Pick the model whose curve passes slightly above the duty point, so the pump does not run far from its best efficiency. Check the suction lift as well, since a high lift and a long suction line reduce the priming performance. For liquids with solids, the open impeller passes particles up to 6 mm.

Tapflo CTS-I compared with standard CT pumps

The standard CT pump must be flooded, with the liquid above the pump. The CTS-I does not need this, because the priming chamber keeps liquid for re-priming and the pump can lift from below.

Tapflo CTS-I temperature and viscosity

The liquid temperature is limited to 90 degrees C. Viscosity should not be higher than about 200 cSt.

Documents and quotation

The CTS brochure and IOM manual list dimensions, curves for 50 Hz and 60 Hz, and the motor sizes. Provide the liquid, temperature, viscosity, suction lift, flow, head and supply frequency for a quotation. Tapflo lists self-priming ability, ideal handling of highly aerated liquids, easy installation and maintenance, and a simple compact design as the main features; the pumps are REACH and RoHS compliant. Typical CTS-I applications are oils, fuels, solvents, concentrated or diluted acids and alkalis, cleaning agents, wastewater, cooling and heating media, and feeding or unloading storage tanks, containers, filters and sumps. Compare other self-priming and centrifugal pumps or the Calpeda NM 50/12F/C for a monobloc option.