Brochure

Packing Seal % Rated Life Versus Static Pressure
F-27414-1 © Copyright 2006 TAC. All Rights Reserved. 171
Valve Packing Life
Valve packings are designed to provide many years of useful
life before they must be replaced.
The actual life, under the standard specified conditions, will
vary ⎯ depending on the frequency of valve cycle and the
condition of the fluid controlled. The more frequently the valve
is cycled and the more contaminated the fluid is with dirt and
harsh chemicals, the shorter the life of the packing.
Water and Steam System Guidelines for Valves
All heating and cooling systems are susceptible to valve and
system problems caused by improper water treatment and
system storage procedures.
These guidelines are to help you avoid valve and water
system problems resulting from improperly treated water or
storage procedures in your cooling and hot water systems,
and to obtain maximum life from your TAC valves.
Durability of valve stems and packings is dependent on
maintaining non-damaging water conditions. Inadequate
water treatment or filtration, not in accordance with chemical
supplier/ASHRAE handbook recommendations, can result in
corrosion, scale, and abrasive particle formation. Scale and
particulates can result in stem and packing scratches; and
can adversely affect packing life and other parts of the
hydronic system.
To maintain non-damaging conditions, clean the system prior
to start up. Use a nitrite or molybdate based treatment
program. Use filtration equipment where needed. Properly
store off-line systems and monitor water treatment results
using corrosion test coupons.
Follow the advice of a water treatment professional. Consult
EN-205 Water and Steam System Guidelines,
Engineering Information, F-26080, for further details.
Seal
Rat
e
Life
Ver
s
Stat
i
TABLE 1. Flow Conversion Factors.
TABLE 2. Pressure Conversion.
U.S. Metric U.K.
Cv Kvs Cvs
US Gal/min m3/hr UK gal/min
1.0 0.865 0.833
1.156 1.0 0.962
1.201 1.039 1.0
1.0 psi = 6.894 kPa
1.0 kPa = 0.145 psi
100 kPa = 14.5 psi = 1.0 Bar