Cheonsei Metering Pump Models: Solenoid, KD, KH, KP and More

Cheonsei metering pump models fall into three groups: the SP-B solenoid pump, the motor-driven KD, KH and KP series, and the A-type automatic pumps plus the small AX and KS lines. Pick the group from your flow and pressure first, then go into the series table.

We get a lot of requests from buyers holding a worn nameplate, or a spare parts list, who only know they have "a Cheonsei diaphragm pump". This guide does not decode the model string letter by letter. That is covered in our KD model code guide. Here we lay out the whole range of Cheonsei metering pump models so you know which series covers which job.

How Cheonsei metering pump models are grouped

The split is by drive. A solenoid pump uses an electromagnet to push the diaphragm. It is compact, simple and suited to small flows. Motor-driven pumps use a motor and reduction gear to move a diaphragm or plunger, and they reach far higher flow and pressure.

On site the check takes a few seconds. No motor, just a square control box with two knobs, and it is a solenoid unit. A vertical or horizontal motor bolted on means you are looking at one of the mechanical Cheonsei metering pump models.

SP-B solenoid metering pump

SP-B is the entry point of the Cheonsei metering pump models: a basic manual solenoid pump, with B standing for Basic & Manual. The front panel has a stroke length knob and a stroke rate knob, and the housing is rated IP65. The catalogue lists SP-B30, B50, B70, B100 and B200, and the first four also come in an H high-pressure version.

From the spec sheet, SP-B30 delivers up to 25 mL/min at 14 bar, while SP-B200 reaches 240 mL/min at 2 bar. Maximum stroke rate is 240 SPM and stroke length adjusts from 40 to 100 percent. Heads come in PP or PVDF with a PTFE diaphragm.

Typical jobs are boiler chemicals, hypochlorite disinfection and small water treatment systems, usually well under 15 L/h.

KD mechanical diaphragm series

KD is the workhorse among Cheonsei metering pump models. It covers 20 to 45,000 mL/min in KDV vertical and KDH horizontal motor layouts. Effective adjustment is 20 to 100 percent, and the pump self-primes about 1 m at full stroke. Liquid ends come in PTC, FTC, STS and 6T6. The first two handle liquid at 0 to 50 ℃, the last two up to 80 ℃.

For layout choice see KDV vs KDH, and for chemical compatibility see KD wetted materials.

KH hydraulic diaphragm series

Among the hydraulic Cheonsei metering pump models, KH also comes as KHV vertical and KHH horizontal. The catalogue runs from KHV,H-51 up to KHV-24. A hydraulically balanced diaphragm lasts longer than a mechanically driven one, so KH suits higher pressure and long continuous duty. The large KHV-14 and KHV-24 reach well over 10,000 mL/min. For the pressure rating of each size, refer to the manual for that model.

KP plunger series

The KP line is the plunger branch of the Cheonsei metering pump models, in KPV and KPH layouts, with L and M suffixes for plunger sizes, from KPV-061L to KPV-502M. Plungers reach pressures diaphragm pumps cannot, and the small sizes go beyond 100 bar. The trade-off is packing: it needs regular leak checks and replacement, and it is a poor fit where zero external leakage is required.

A-type automatic pumps and small pumps

KD-A, KHV-A, KPV-A and KM-A

These Cheonsei metering pump models use a BLDC brushless motor with a built-in microprocessor. They accept a 4-20 mA input for automatic flow control and give an isolated 4-20 mA feedback output. The catalogue states an effective range of 5 to 100 percent of full scale with ±2 percent accuracy. KM-A runs on single-phase 110 to 220 V only.

AX and KS minis

AX covers AX1-21, 51, 12, 32, 52 and 13, single-phase 220 V with a built-in thermal switch, in standard and high-viscosity versions plus a boiler option. KS includes KS-51, 12, 22, 32 and 52, with a 40 W motor and planetary gear drive for liquid at 0 to 50 ℃. Both are common on lab rigs, small boilers and OEM equipment.

Accessories that belong on the same order

The catalogue also lists pulsation dampers, back-pressure valves and relief valves. Diaphragm and plunger output is pulsed, so long lines or low discharge pressure without a back-pressure valve can cause siphoning and overdosing. Where a discharge valve could be closed by mistake, fit the relief valve between pump and valve. When you compare Cheonsei metering pump models, put accessories on the list too.

From series to a specific model

Narrowing Cheonsei metering pump models down to one size takes five steps.

1. Fix maximum flow and highest discharge pressure.
2. Choose liquid end material and check liquid temperature.
3. Decide whether you need remote 4-20 mA control. If yes, go straight to the A-type.
4. For toxic or costly chemicals, prefer hydraulic diaphragm over plunger.
5. Check the series table for power supply and mounting.

Original catalogues for KD, KH and SP-B are on our downloads page, and general solenoid options are under solenoid metering pumps.

Safety note: before removing an old pump, stop it, relieve pressure and drain the chemical from the lines.

Conclusion

The range of Cheonsei metering pump models is easy to remember: SP-B for small solenoid dosing, KD for everyday chemical feed, KH for high pressure and long duty, KP for the highest pressure, the A-type for automatic control and AX or KS for compact equipment. Final sizing depends on flow, pressure and chemical. Send a nameplate photo or your duty data through our contact page and we will match the model.

FAQ

How do I read a Cheonsei model code?

The code typically combines series, size, pressure class and material. Our KD model code article walks through it.

SP-B or KD, which one?

Small dose and low pressure point to SP-B, which is cheaper and easy to mount. Larger or continuous duty points to KD.

KH and KD look similar. What is the difference?

KH has a hydraulically balanced diaphragm and KD a mechanical one. KH handles higher pressure and its diaphragm lasts longer.

Can the A-type connect to a PLC?

Yes, a 4-20 mA input sets the flow automatically. The isolated 4-20 mA feedback can go back to the PLC.

The nameplate is unreadable. How do I identify the pump?

Measure the head and connection sizes, then photograph the motor and gearbox. Most Cheonsei metering pump models can be identified that way, at least the series, and the size can be confirmed after.