BA HERCS, Model VIG 2, all in one, self- contained non electric control valve that has been developed for domestic hot water (DHW) production in systems with or without hot water service tanks and charging systems for hot water service tanks. The controller is used for temperature controlling with steam or hot water up to 235° F (110° C)

 The temperature controller is a self-acting proportional controller for temperature control and monitoring, operate according to the liquid expansion principle.

 The control valve combined with a safety temperature limiter that will shut down the valve when the high temperature set point is reached. No electric solenoid valves needed. 

 Valves sizes from ½” (DN 15) to 1 ½” (DN )

Valves come with 2 DIN flanges, bolts and gaskets.

Valves come in 2 way or 3 way configurations.

Max pressure/ temperature:

Valve – 362 PSI (25 bar)/ up to 302° F  (150° C)

Temperature Sensor – 362 PSI (25 bar)/ 347° F (175° C)

Technical Data

Nominal pressure: 362 PSI (25 bar)/ flanges to DIN 2501

Flow medium / Temperature Steam / max. 662° F  (350° C)

Pressure balance, Stainless steel bellow, mat. No.1.4571, Rolling diaphragmValve body material:

362 PSI (25 bar) Ductile iron EN-GJS-400-18-LT (GGG-40.3)

Cone material: Stainless steel, mat. No. 1.4021 No. 1.4313

Seat material: Stainless steel, mat. No. 1.4021

Mode of Operation

The controllers are proportional controllers

and the valves are pressure-balanced.

Safety Temperature Monitor (STW) Function STW

When reaching the set limit temperature at the temperature sensor (5), the safety temperature monitor interrupts energy supply by closing the valve (1). As soon as the temperature at the temperature sensor drops, the valve is opening automatically. The limit temperature is adjusted at the setpoint

adjuster (3.1) with temperature scale. The setpoint adjuster can be sealed.

Extended Safety STW

If there is a leakage in the temperature

sensor, the connection pipe, or the

thermostat, the valve is closed by a pressure

spring in the safety thermostat.

Physical Function Principle STW

The safety thermostat (3) operates in

accordance with the liquid expansion

principle. The temperature sensor, the

connection pipe, and the working element are

filled with liquid. As the temperature at the

temperature sensor rises, the liquid expands,

the working stem of the thermostat is pressed

out and the valve VIG 2 is closed.

Mounting

 A strainer must be installed in front of the controller: Nom. diameter ½” & ¾” (DN 15 – 25)

0.5 mm  Nom. diameter  1 ¼” & 1 ½” (DN 32 – 40)

Strainer mesh size 0.8 mm The controller may be installed in any position.

Valve Body

Construction

1 Valve VIG 2

2 Trim

2.1 Valve plug

3 Safety thermostat STIW

3.1 Setpoint adjuster with

safety bore

4 Thermostat AIT

4.1 Setpoint adjuster with

safety bore

5 Temperature sensor

6 Immersion pocket

7 Combination piece KI1

Temperature Controller (TR)

Function TR

The temperature of a medium is controlled by the temperature controller (TR) in accordance with the adjusted setpoint. The setpoint is adjusted by turning the setpoint adjuster(4.1). The setpoint adjuster may be sealed.

Physical Function Principle TR

The thermostat AIT(4) operates in accordance with the adsorption principle. A pressure is generated in the temperature sensor (5) which is proportional to the medium temperature. The pressure is transferred via the connection pipe to the metal bellows of the thermostat. The stem of the thermostat is pressed out and the valve VIG2 is closed.

The sensor must be immersed into the medium by its full length. Select the location of installation in such a way that the highest temperature of the medium is measured directly and without any delay. The setpoint adjusters of the thermostats STIW, AIT may be sealed. For temperatures higher than 248°F (120 °C), the safety temperature monitor must be secured with a seal.