Tunstall Macon STV Series Manual page 152

GUIDE SPECIFICATIONS – AUTOMATIC BALANCING VALVES
MANUFACTURER
1. Macon Balancing, Models AB, ABW, ABG and AW.
DESIGN
1. The GPM for the automatic balancing valves shall
be factory set and shall automatically limit the rate
of flow to with in ±5% of the specified GPM over
at least 95% of the control range.
2. For .50" through 2.0" the flow cartridge shall be
removable from the Y Body housing without the
use of special tools to provide access for cartridge
change-out, inspection and cleaning without
breaking the main piping.
3. PUMP HEAD REQUIREMENT:
The permanent pressure loss added to the pump
head shall not exceed seven feet.
4. Each valve shall have 2 P/T Ports.
5. The valve handle shall be fitted with a fine tuning
memory stop handle to allow for adjusting the
control range.
CONSTRUCTION
1. The internal wear surfaces of the valve cartridge
shall be Ultrason ® Composite or stainless steel.
2. The flow cartridge shall be permanently marked
with the GPM and differential range.
3. For .50" through 2.0" pipe sizes: An assembly
shall consist of a brass Y-type body, integral
brass-body ball valve and O-ring type union.
Macon model AB.
4. For 2.5" and larger flanged connections:
Ductile-iron body, suitable for mounting wafer
style between standard 150# or 300# flanges.
The long flange bolts and nuts shall be provided
with each control valve.
Macon model AW.
MINIMUM RATINGS
1. For .50" through 2.0" pipe sizes
600 PSI @ 250°F.
2. For 2.5" through 12.0" pipe sizes
600 PSIG @ 250°F.
FLOW VERIFICATION (choose one)
1. The differential pressure across the Automatic
Balancing Valve shall be measured for flow
verification and to determine the amount of system
over heading or under pumping.
2. The flow shall be verified by measuring the
differential pressure across the coil served or the
wide open temerature control valve and calculating
the flow using the coil or valve Cv.
TEST KIT
1. A pressure and temperature test kit shall be
provided with the ability to read differential
pressure from 0 to 75 PSI, and temperature
from -10 to 230° F.
INSTALLATION
1. Install automatic balancing valves on the
return lines of coils as indicated on the plans.
A balancing valve on the supply side is not
acceptable.
2. The standard ports and handle shall clear 1.0"
thick insulation. Do not insulate flow control valves
used on heating coils.
3. Install, on the supply side of coils, a Y-strainer
with brass blow down valve with .75" hose-end
connection with cap. Inline basket strainer is
not acceptable.
152
Tunstall Corporation
118 Exchange Street
Chicopee, MA 01013
Form # GS-AB-03.14