Honeywell DU146M User Manual

AUTOMATIC BYPASS AND DIFFERENTIAL PRESSURE VALVE

FOR INSTALLATION IN DISTRICT HEATING SYSTEMS

Design

The automatic bypass and differential pressure valve comprises:

•

Body with internally threaded inlet and outlet

•

Spring bonnet

•

Adjustment facility

•

Valve disc

•

Spring

Materials

•

Unpolished brass housing

•

Untreated brass spring bonnet

•

High-quality synthetic material adjus ter knob

•

Brass valve disc

•

Stainless-steel spring

•

EPDM seals

DU146 M

PRODUCT DATA

Application

The DU146 M automatic bypass and differential pressure valve is used to maintain constant differential pressure in a heating system. It reduces flow noise in a system, particularly as thermostatic radiator valves are closing. The boiler return temperature is raised and this reduces the corrosion caused by flue gas condensation. In addition, when radiator valves are closed it also maintains flow over the temperature sensor on the boiler to ensure proper operation of external temperature compensating controls. On gas fired water heaters it guarantees a minimum flow circulation when thermostats or radiator valves are closed.

Features

• Simple installation between the flow and return pipe-

work

• Minimises flow noise

• No external controls required

• Differential pressure finely adjustable

• Problemlose Einregulierung durch eingebaute

Differenzdruck-Istwertanzeige

• Hinders boiler corrosion

• Setting value is in meters water column

• Tried and tested

Range of Applicati on

For pumped hot water heating systems

Specifications

Medium Operating temperature Operating pressure Differential pressure

Connection size

Hot water max. 130°C (230°F) max. 16 bar (232 P.S.I.) Adjustable between

0,05...0,5 bar (0,7...7,3 P.S.I.) Set during manufacture at

0,2 bar (2,9 P.S.I.) 3/4" and 1 1/4"

DU146 M

Function

At equal pressure between the inlet and outlet side the valve is closed. The valve disc is pushed by a spring against the valve seat. If there is a pressure difference between the inlet and outlet sides, then a force is exerted on the valve disc and against the spring. If this force exceeds the force of the spring, then the valve begins to open in proportion to the rise in differential pressure and maintains a constant bypas s flow as indicated on the flow diagram.

Versions

A = Standard version Special version on request

Dimensions Flow rate V m3/hType R

L I H h

3/4" 36 50 160 100 3 DU146M-3/4A

1 1/4" 51 58 213 155 10 DU146M-1 1/4A

Ordering-No.

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