200X for fixed downstream pressure

Choose the Pressure Reducing Valve (200X) when the system needs a fixed outlet pressure. Its documented function is to hold the outlet pressure steady against upstream pressure fluctuations and changes in downstream water demand. It is intended for domestic water supply, fire protection, and industrial water-supply systems. On the procurement side, keep “reducing outlet pressure” separate from “sustaining upstream pressure.” The confirmed function of the 200X is fixed outlet-pressure control.

300X for controlled check-valve closing

Choose the Slow-Shutoff Check Valve (300X) where pump starting and stopping require adjustable opening and closing speed. The valve can be adjusted on site to reach a suitable operating speed. Its documented purpose is to reduce water hammer and close more quietly. The stated application is high-rise buildings. Base selection on the need for check-valve action with controlled movement, not on pressure reduction or continuous flow regulation.

400X for predetermined flow

Choose the Flow Control Valve (400X) when the required result is a predetermined downstream flow. The valve maintains the preset flow, limits excessive flow to that preset value, and reduces high upstream pressure as appropriate. According to the product documentation, changes in upstream pressure do not affect downstream flow. The valve can also stop flow in an emergency. Keep this model clearly apart from the 200X during inquiry review. The 200X controls outlet pressure; the 400X controls flow.

500X for pressure sustaining or relief duty

The Pressure Sustaining / Relief Valve (500X) is listed under that product name, but a detailed factory description of its control sequence and application has not been confirmed. Do not select the 500X from its model number alone. State whether the duty is pressure sustaining or pressure relief, and get written confirmation of the required function and configuration before ordering.

600X for electrically commanded operation

Choose the Electric Control Valve (600X) when the main valve has to open or close remotely in response to an electrical signal. The 600X uses a solenoid valve as its pilot. It is intended for automatic control in water supply, drainage, and industrial systems, and it can replace a gate valve or butterfly valve in large electrically operated systems. The available documentation does not state solenoid voltage, pilot connection, or pilot-pipe material. Confirm these for each order.

800X for differential-pressure bypass control

Choose the Differential Pressure Bypass Valve (800X) for differential-pressure control between the supply and return water lines of an air-conditioning system. Its function is to hold differential pressure constant. The documented objectives are better system utilization and less noise and equipment damage from excessive differential pressure. Do not specify the 800X as a general pressure-reducing valve. Its identified control duty is differential pressure across the supply and return sides of the system.

Are all 100X to 800X valves used for pressure control?

No. The series covers water-level, outlet-pressure, check-closing, flow, electrical on/off, pressure sustaining/relief, and differential-pressure functions. Select the model according to the required control duty.

What is the difference between 200X and 400X?

The 200X maintains a fixed outlet pressure despite changes in upstream pressure or downstream demand. The 400X maintains a predetermined flow and limits excessive flow to that value.

Can the 100X float be installed away from the main valve?

Yes. The control float can be installed separately from the main valve body. Confirm the arrangement against the tank and pipeline layout.

Does the 300X help with pump start and stop conditions?

Yes. Its opening and closing speed can be adjusted on site, with the documented purpose of reducing water hammer and closing more quietly during pump operation.

Can the 600X be controlled remotely?

Yes. It uses a solenoid pilot and can open or close according to an electrical signal. Solenoid voltage and related pilot specifications are not listed and require confirmation.

Is the 800X the same as a conventional pressure-reducing valve?

No. The 800X is identified for differential-pressure control between air-conditioning supply and return water lines. The 200X is the model identified for fixed outlet-pressure control.

Is DN50 to DN400 confirmed for every project?

It is the range currently listed for all seven product models, but separate written factory confirmation is not available. Confirm the required nominal size in the final order documentation.

Hydraulic Control Valve Selection Guide

How the 100X to 800X series differs

Red hydraulic control valve with a pressure gauge on the control line, photographed on a white background — The same pilot-operated family in a larger bore. The body carries only the seat, disc and diaphragm; the duty is set by the pilot valve bolted to the cover.

These are pilot-operated hydraulic control valves. Each one is a main valve plus pilot valves and pilot piping. What separates the models is the pilot configuration: a float pilot, a pressure-reducing pilot, a flow-control pilot, a solenoid pilot, or a differential-pressure pilot.

Model numbers are therefore not interchangeable size variants. They identify different control duties.

The listed series usually covers DN50 to DN400. That range appears on the current product pages but has no separate written factory confirmation behind it, so the final size has to be stated on the confirmed order document.

Model	Listed valve type	Primary control duty	Documented application
100X	Remote Float Control Valve	Tank or reservoir water level	Domestic water supply, fire protection systems, industrial water supply
200X	Pressure Reducing Valve	Fixed outlet pressure	Domestic water supply, fire protection systems, industrial water supply
300X	Slow-Shutoff Check Valve	Adjustable opening and closing speed	Pump start and stop applications in high-rise buildings
400X	Flow Control Valve	Predetermined downstream flow	Flow regulation and emergency flow shutoff
500X	Pressure Sustaining / Relief Valve	Pressure sustaining or relief	Detailed factory application description not confirmed
600X	Electric Control Valve	Remote opening and closing by electrical signal	Automatic control in water supply, drainage, and industrial systems
800X	Differential Pressure Bypass Valve	Constant differential pressure	Air-conditioning supply and return water systems

Select the model by control objective

Hydraulic control valve with two pressure gauges on the control circuit, photographed on a white background — Two gauges on the circuit let a commissioning engineer read both sides of the differential-pressure duty at once.

A practical inquiry checklist

Cross-section diagram of a pilot-operated hydraulic control valve with diaphragm chamber, needle valve and pilot valve — Pilot-operated hydraulic control valve in section: the main valve is common across the 100X-800X series and the pilot valve sets the function. Cross-section diagram - illustrative, not a specification.

A useful purchase inquiry identifies the required control duty first:

1. State whether the valve must control water level, outlet pressure, pump-related closing speed, flow, electrical opening and closing, or differential pressure.

2. Identify the system as domestic water supply, fire protection, industrial water supply, drainage, a high-rise building installation, or an air-conditioning supply and return system, where applicable.

3. Give the required nominal size for confirmation.

4. For 100X, describe the required float location relative to the main valve.

5. For 600X, state the required electrical control details and ask for confirmation of the solenoid specification.

6. For 500X, state clearly whether the intended duty is pressure sustaining or pressure relief.

7. Ask for written confirmation of all unlisted construction and connection details before finalizing the purchase.

This keeps selection focused on the actual control objective and stops an unconfirmed specification from being inferred from the model number.

What remains unconfirmed

Valve body, disc, seat, or diaphragm materials
Pressure rating, including PN or Class
Applicable manufacturing or testing standards
Temperature range
General medium compatibility
Connection type
Flange drilling standard
Pilot-valve connection details
Pilot-pipe material
Solenoid voltage for the 600X
Detailed operating description for the 500X

Reference sources

Frequently Asked Questions

Choose the Remote Float Control Valve (100X) when the control variable is the water level in a tank or reservoir. The medium carries the control condition through pilot piping to a small float pilot valve. At low water level the pilot opens and the main valve supplies water. At the high-water level the pilot closes and the main valve closes with it. The control float can be installed separately from the main valve body. That matters when the float has to follow the tank water level while the main valve sits elsewhere in the pipeline.

Related Products

Remote Float Control Valve (100X)

100X · DN50 – DN400

Pressure Reducing Valve (200X)

200X · DN50 – DN400

Slow-Shutoff Check Valve (300X)

300X · DN50 – DN400

Flow Control Valve (400X)

400X · DN50 – DN400

Pressure Sustaining / Relief Valve (500X)

500X · DN50 – DN400

Electric Control Valve (600X)

600X · DN50 – DN400

Hydraulic Control Valve Selection Guide: 100X to 800X Series

How the 100X to 800X series differs

Select the model by control objective

A practical inquiry checklist

What remains unconfirmed

Reference sources

Frequently Asked Questions

Need valves or wear parts for your next project?

Hydraulic Control Valve Selection Guide: 100X to 800X Series

How the 100X to 800X series differs

Select the model by control objective

A practical inquiry checklist

What remains unconfirmed

Reference sources

Frequently Asked Questions

Related Products

Related Guides

Need valves or wear parts for your next project?