Honeywell VK4125A1025 gas valve

The Honeywell VK4125A1025 gas regulator is part of the burner control and ignition system, which provides safe ignition, flame control and gas flow control for the pilot and/or main burner. This system includes the VK4100C 1067 gas valve itself and a special ignition regulator that is attached to it.

The Resideo VK4125 A 1025B gas valve has a standard housing and can be configured with various options, such as:

• Pressure regulation by means of a servo drive.

• Regulation by means of a throttle valve.

• Smooth ignition using the SOFTLITE system.

• Gas and air regulation with a ratio of 1:1.

• Electric two-level regulator.

• Smooth regulation with amplification for various types of control.

The Honeywell VK4125A 1025B gas solenoid valve has two electrical devices: one for controlling the main valve and the other for controlling its position.

This gas solenoid valve can work with three types of gas: heating gas, natural gas and liquefied gas.

General characteristics

1. The inlet and outlet are suitable for flanged connection

2. Screen: On the input side

3. Pressure valve: Top to measure inlet and outlet pressure

4. Gas connection: Inlet: 1/2″ BSP.Pl Outlet hole: 1/2″BSP.Pl

5. Back pressure: 1st valve: 50 mbar; 2nd valve: 50 mbar

6. Ambient temperature: -15 … 60°C

7. Maximum inlet pressure: 60 mbar

Management functions

• Maximum operating pressure: 45 mbar

• Leakage requirements: According to EN126

• Performance (by air): 2.4 miles/5 mbar thermal pressure drop

• Performance curve: H30

Electrical characteristics

• Ratings: 220 … 240 V AC; 50 Hz

• Load: 1st + 2nd operator 48 mA at 220 V AC

Standard working conditions

• Nominal inlet gas pressure of 25 millibars, dry air at 20°C.

• Recording the output pressure using a sensor connected to a 1/2-inch diameter pipe, 10 times the diameter, through a short hose with a length equal to 5 pipe diameters.

• Ambient temperature 20°C.

• 2.8 mm aperture.

• Display of gas consumption in cubic meters per hour.

• Ambient pressure 1013 millibars.

• Operation at rated voltage.

• Installation in a vertical position.

General provisions

The Honeywell VK4125A1025B gas valve combines all the safety and burner control functions in one reliable system. The inlet and outlet of the valve have a diameter of 18.6 millimeters and can be connected via flanges. There are different models of this valve with different levels of closing force: B + J, B + C, B + B.

There is a built-in fine-mesh filter at the inlet of the VK4125 A 1025U gas regulator, which is not intended for cleaning. An additional output filter can be added if necessary. There are holes at the bottom of the valve for mounting to the installation.

There are variants of gas valves with side gas outlet for both the main and pilot burners. However, such a side outlet can only be used with a flanged burner manifold. In addition, there is a connection for pilot gas with a diameter of 4 mm at the outlet of the Honeywell VK4125A 1025U gas regulator. It is also possible to install pressure measuring fittings using silicone tubes with a diameter of 4 or 6 mm.

It is worth noting that there is a choice of different types of electrical connections, such as connecting to the ignition regulator using a connector or using a plug-in rectifier unit for a standard DBI ignition system. In addition, it is possible to choose options for operation at a voltage of 24V for joint use with other ignition regulators, excluding regulators of the S4565/S4585 series.

The principle of operation

As for the principle of operation, VK4125A1025U gas regulators use a positive feedback system (the main valve automatically closes when there is no power supply or gas pressure is exceeded). The system includes a pressure servo controller and a pressure relief valve that work together. When the power supply is supplied, the gas passes through the servo controller and opens the main valve. The system then maintains a constant pressure by regulating the operation of the main valve. This guarantees a stable output pressure, even with changes in the input pressure.