User Guide

F-24389-2 © Copyright 2008 TAC All Rights Reserved. 7
Note: Add 14.7 psi to gauge supply pressure to obtain absolute pressure value.
For example, if a valve is controlling 200°F water at an inlet pressure of 18 psig, the
maximum pressure drop allowable would be:
Pm = 0.5 [(18 + 14.7) – 11.53] = 10.6 psi
(Vapor pressure of 200°F water is 11.53 psia.)
If the pressure drop for this valve is less than 10.6 psi, cavitation should not be a problem.
Systems where cavitation is shown to be a problem can sometimes be redesigned to provide
lower inlet velocities.
Table-7 Vapor Pressure of Water Table.
Additional Valve
Sizing Information
For additional valve sizing information, see:
• CA-28 Control Valve Sizing, F-13755
• Valve Selection Chart Water, F-11080
• Valve Selection Chart Steam, F-11366
• Valve Sizing Slide Rule, TOOL-150
INSTALLATION
Inspection Inspect the package for damage. If damaged, notify the appropriate carrier immediately.
If undamaged, open the package and inspect the device for obvious damage. Return
damaged products.
Requirements • Tools (not provided): Pipe wrenches
• Training: Installer must be a qualified, experienced technician
• Appropriate accessories
Caution:
• Install the valve with the flow in the direction of the flow arrow (“A” port is the inlet and
“AB” port is the outlet).
• Do not exceed the ratings of the device.
• Avoid locations where excessive moisture, corrosive fumes, or vibration are present.
Mounting 1. The valve should be mounted in a weather-protected area in a location that is within the
ambient limits of the actuator. When selecting a location, allow sufficient room for valve
linkage, actuator, and other accessories and for service of the product.
2. The preferred mounting position for the valve is with the valve stem vertical above the
valve body. Avoid mounting the valve so that the valve stem is below horizontal.
3. On steam applications where the ambient temperature approaches the limit of the
actuator, the valve stem should be mounted 45° from vertical.
4. The VB-7263-0-4 series screwed valve bodies conform to American Standard Taper
Pipe Threads (NPT). The valves must be piped with the “A” port as the inlet and the “AB”
port as the outlet.
Water
Temp.
(°F)
Vapor
Pressure
(psia)
Water
Temp.
(°F)
Vapor
Pressure
(psia)
Water
Temp.
(°F)
Vapor
Pressure
(psia)
Water
Temp.
(°F)
Vapor
Pressure
(psia)
40 0.12 90 0.70 140 2.89 190 9.34
50 0.18 100 0.95 150 3.72 200 11.53
60 0.26 110 1.28 160 4.74 210 14.12
70 0.36 120 1.69 170 5.99 220 17.19
80 0.51 130 2.22 180 7.51 230 20.78