
Series PVM
Optional features and accessories available for this
Macon product are an extra charge, and not included
in the standard model price.
www.maconbalancing.com
Tunstall Corporation
118 Exchange Street · Chicopee, MA 01013
Phone (413) 594-8695 · Fax (413) 598-8109
Section:
Components
Bulletin-MB-PVM-0915
STANDARD APPLICATION
PVM is fitted in the intake, the signal pipe is to be
connected at the low pressure side of the STV valve, The
valve can be fitted irrespective of whether it is a straight
length of pipe. Bends, tubes etc. can be
installed immediately after the valve.
1. Flush the valve before fitting signal pipe
2. Install t-pipe with measurement socket on the STV valve.
3. Install signal pipe, on the t-pipe and flush to ensure that
there is no air in the signal pipe.
4. Install the signal pipe on the PVM valve on
the return pipe.
DIMENSIONING
Selecting the right valve in an installation requires
some data about the system.
△
P pump available differential pressure from pump
△
P load
differential pressure for circulation
△
P STVP pressure drop over valve fully open (diagram)
△
P PVM pressure drop over the PVM valve
(diagram)
Example
:
Calculated value for a valve is 6.34 gpm.
7.25 psi is available differential pressure for
circulation
△
P load 2.9 psi is required for the main.
We find the minimum differential pressure required for the
PVM valve to achieve minimum working pressure in the dia-
gram.
Two valves can deliver 6.34 gpm 1” and 1 1/4”.
ADJUSTMENT AND MEASURING
When adjusting the differential pressure on the PVM valve,
measure and adjust to 10 kPa, making sure at least one radia-
tor valve is slightly open.
When measuring the flow, use the STV valve and a measur-
ing tool. The STV valve’s wheel may be set lower to have a
higher differential pressure over the PVM valve. Note that the
differential pressure over the STV valve will not be too high
so that the min differential pressure over the PVM valve will
be to low and the PVM valve will stop regulating. Open the
STV valve completely after measuring the flow.
OPTIMIZING PUMP PRESSURE
Lowering to minimum possible pump differential pressure is
carried out by measuring at the PVM valve and obtaining at
least 1.91 psi, this is the pump’s lowest level at which the
PVM can be regulated.
PRESS. DIF
F
.
REGULA
T
O
R
71
Summary of Contents for Macon AB Series
Page 38: ...This page left blank intentionally MANUAL 38 ...
Page 48: ...STRAINERS This page left blank intentionally 48 ...
Page 52: ...This page left blank intentionally SHUT OFF VALVES 52 ...
Page 56: ...This page left blank intentionally UNIONS 56 ...
Page 74: ...74 ...
Page 122: ...122 ...
Page 144: ...144 ...