Cheonsei Metering Pump KDV vs KDH: Vertical or Horizontal Drive?

Most buyers looking at a Cheonsei metering pump for the first time get stuck on one letter in the model code. Is it KDV or KDH? On the phone the question is usually "which one is better?" The honest answer is that neither is better. Both use the same liquid ends, and the small and mid-size models match one for one. What changes is where the motor sits, and that matters more for installation and service than for dosing.

A Quick Look at the Cheonsei Metering Pump KD Series

Cheonsei is a Korean manufacturer, and its KD series is sold under the KEMPION trademark. Each Cheonsei metering pump in this line is a mechanical diaphragm design. The motor drives a worm gear reducer, an eccentric cam turns rotation into a reciprocating slider, and a return spring works with the slider shaft to flex the diaphragm. Flow is set by stroke length, and you can adjust it with the pump running or stopped. The effective adjustment range is 20% to 100% of stroke.

In the code, D means diaphragm, and the letter right after it is the drive construction. V is vertical. H is horizontal. The Chinese manual describes the vertical drive as direct-coupled and the horizontal drive as indirect, and the horizontal parts list includes a separate coupling guard.

KDV vs KDH: What Actually Looks Different

The dimension drawings in the Cheonsei metering pump catalog tell the story. On a KDV, the motor stands upright on top of the gearbox. The base is small and the unit is tall. On a KDH, the motor lies on its side next to the gearbox. The pump sits lower but stretches out sideways.

On site that difference is practical:

• A dosing room with good ceiling height and limited floor space suits vertical pumps lined up side by side.
• A pump going into a cabinet, or under pipe racks and cable trays, is easier to fit as horizontal.
• On a skid with a fixed base plate, a replacement Cheonsei metering pump should follow the original orientation.

Weight differs too. For the same Cheonsei metering pump model, the horizontal version is usually a few kilograms heavier. The small 21H, 61H and 12H models weigh 14 kg vertical and 17 kg horizontal. The 33H and 73H are 47 kg vertical and 51 kg horizontal.

Not Every Cheonsei Metering Pump Has a Horizontal Version

This catches people out. In the manual's specification table, every size from 21H to 14M lists both a vertical and a horizontal weight, and the horizontal drive drawings stop at 14M. Above that, the 14H, 14G, 24L, 24S, 24H, 34H and 54L show only a vertical weight.

So if your duty falls in the large-flow range, such as the KDV-54L (about 45000 mL/min maximum at 50 Hz, 3 bar maximum), the literature basically offers vertical only. If you really need horizontal, ask the factory first instead of drawing it into the layout and finding out later.

At the small end of the Cheonsei metering pump range you have more freedom. KDV-21H and KDH-21H both deliver 20 mL/min maximum at 50 Hz and 10 bar maximum. On 60 Hz power the same model gives a bit more, 25 mL/min for the 21H.

When we help customers pick a Cheonsei metering pump, we always choose the model first and the construction second. Get flow, pressure and wetted materials right, then decide whether the pump sits better upright or lying down. Start with "I want horizontal" and you often discover the flow range you need has no horizontal option.

Need 4-20mA Control? Check the Mounting First

Cheonsei offers a KDV-A automatic control version of its metering pump. It uses a brushless DC motor with a built-in controller, takes an external 4-20mA signal to set flow, and provides a 4-20mA feedback output, so it connects easily to a PLC. The brochure is explicit: on these 4-20mA automatic models the motor is vertically mounted.

For projects that tie dosing to an online analyzer, you'll be choosing within the KDV range. The newer English catalog lists the brushless control unit as option A in the model code, so if you want horizontal plus automatic control, get written confirmation from the factory before ordering.

Installation and Maintenance Pitfalls

Vertical or horizontal, the installation rules for a Cheonsei metering pump are the same. Mount it level with room around it for adjustment and service, ideally below the lowest tank level and away from vibration. Self-priming capacity is only 1 m, so a tank set too low often won't prime. Outdoor pumps need a canopy, and ambient temperature should stay within 0–40°C.

Common problems on site:

1. Ignoring the mounting holes on a replacement. The old pump was horizontal, the new one arrives vertical, and the base holes and port heights no longer match the piping.
2. Putting the coupling guard side of a KDH against a wall, which makes later motor and coupling work very awkward.
3. Leaving too little space above a KDV, so the pump has to come out before anyone can lift off the motor or work on the drive.

Both drive types of the Cheonsei metering pump run in an oil bath. Change the oil within the first 1000 hours, then every 5000 hours. Oil volume depends on the model: about 250 mL for 21H–73L, 1.2 L for 33H–14M, 2.7 L for 14H–24S and 3.5 L for 24H–54L.

Conclusion

The KDV vs KDH decision for a Cheonsei metering pump is simpler than it looks. Pick the model by flow and pressure, then look at the space. Tight floor and good headroom favor vertical. Limited height or a cabinet favors horizontal. Above the 14M size, or with 4-20mA automatic control, the literature points to vertical. When replacing an old pump, match the original construction and hole pattern and you'll save a lot of re-piping.

FAQ

Is dosing accuracy the same for vertical and horizontal?

The two share the same liquid ends and the same specification table, so flow and pressure match. Accuracy depends more on piping, back pressure and calibration than on motor position.

Can I swap an existing KDH for a KDV?

Yes, but expect to modify the base and piping. Outline dimensions and port positions differ, so check the catalog drawings first.

Is there a horizontal KDV-54L?

The manual only gives vertical data for sizes from 14H up. If you need horizontal, confirm with the factory.

Why is the horizontal version heavier?

The literature doesn't say. From the parts lists, the horizontal drive is built differently and adds parts such as the coupling guard. The same model is usually a few kilograms heavier, for example 14 kg versus 17 kg on small sizes.

What information do I need to order?

Liquid name, ingredients, concentration, temperature and viscosity, plus required flow, suction and discharge piping, power supply, ambient temperature and mounting method. Mounting method is where you tell the factory vertical or horizontal.

If you'd like to compare a Cheonsei metering pump with a similar Chinese-made option for your duty, send us site photos and process data through our contact page.