TDS Differential Pressure Controller

The Clorius TDS differential pressure controller, which is made in four variants, have the following major applications:
Control of differential pressure, noise and dynamic balance. In individual users, circuits and sub-mains within a large distribution network. For example, in District Heating or Group Heating networks. Control of by-pass between flow and return where 3-way valves or 2-way zone control valves are installed. To limit volume variations and maximum Δp. Similarly, for low water content, boilers and devices requiring a minimum circulation irrespective of load conditions. With the addition of a miniature solenoid valve in the impulse connection, the valve can also be used to isolate a circuit with respect to time or temperature.

Function

The TDS controller can be installed in either the flow or return of the sub-circuits.
The high-pressure line is connected to the adjustment side of the diaphragm housing and the low-pressure line to the valve body side of the diaphragm. Any change of differential pressure across the diaphragm connected to the valve mechanism – above or below the set point- will cause the diaphragm to change its position. If higher than the set pressure, the valve will move to close. If lower than the set pressure, the valve will move to open until the system is again balanced. Adjustment of the differential pressure setting is made by rotating the adjusting handle clockwise or anticlockwise until the desired set point is reached (see diagram). In conjunction with the scale marked on the spring guide tube, the upper edge of the adjustment cap is an indication of the actual setting. The scale moves into or out of the handle, loading the valve and diaphragm. The set pressure is shown on a percentage scale in 10% increments.

Design

The Clorius TDS controller is a spring-loaded self-acting proportional controller consisting of a valve, a diaphragm and housing and two capillary tubes on either side of the diaphragm.

The valve body, available in DN15 and DN20, is made of hot-pressed brass and the seat and cone of stainless steel. The diaphragm housing is made of nodular cast iron, and the diaphragm itself is made of EPDM rubber with web reinforcement. If required, the TDS controller adjustment handle can be sealed, preventing unauthorised persons from altering the set point.