An early steel valve advertises “steam up to
250 pounds.”
It didn’t take industry long to push
the boundaries of the standard valve
materials of the day. It soon was no
longer feasible to design and manufacture cast iron valves to meet higher
pressures and temperatures produced by
the newest steam boilers.
High capacity steel production began
in the U.S. in the 1860s with the inception of the Bessemer process. This
process made the production of large
batches of steel economical. However,
steel didn’t reach the valve industry for
many years. For nearly 40 years after
those first batches, the primary use of
the steel was producing rails for the
railroad transportation empire spreading across the continent. By the end of
the century, however, new processes for
steel-making had been developed that
greatly increased the productivity of
steel foundry work. These processes,
such as the electric arc furnace, opened
the door for steel usage in the valve and
fitting industry—just in time to meet
the needs of the newer high-pressure,
high-temperature steam generation.
Valves and steel have been a natural
and a long-lived marriage that exists to
this day. The explosion of the steel valve
industry, however, began during the first
decade of the 20th century. No longer
would the brittleness and 23,000 psi
tensile strength of 19th century cast
iron limit valve construction. Instead,
the greater strength (70,000 psi tensile)
and ductile qualities of cast steel opened
new doors for valve design.
VALVE TYPES
While the primary industry focus was on
gate, globe and check valves in the early
days, control and pressure relief valves
also were important. In fact, the first
valve of importance to the steam power
industry was the safety valve. Such
valves were designed to open when dangerous pressures were achieved in the
steam boilers. On the initial designs, an
adjustable, weighted lever-arm was
attached to the closure member (disc) of
the valve. The weight was positioned on
the lever-arm to match the force exerted
on the closure member inside the pressure boundary. As the pressure rose, the
weighted disc moved upward and
relieved pressure. Later designs would
incorporate an adjustable spring to balance the pressure.
As the end of the 19th century
approached, much ignorance existed
about the dangerous side of steam
power. Tragic boiler explosions were
killing and maiming hundreds of persons each year. The fledgling American
Society of Mechanical Engineers
(ASME) focused on this problem, and
by 1912 had a solution in place in the
creation of the Boiler and Pressure Vessel Code. “The code,” as it is referred to
today, helped solidify safety relief valve
design and performance.
Control valves were important in
19th century piping systems as well.
These valves were initially called gover-
Valves go back as far as the Roman Empire.
The very first patent for a valve in the U.S.
was filed by James Robertson in 1840.
nors, pressure-reducing valves, back
pressure valves or automatic relief
valves. The control valve industry, like
other valve industry segments, received
its initial impetus from the control and
regulation of steam power.
By 1900, the valve industry was very
healthy and gaining maturity rapidly;
however, virtually every manufacturer
was doing things its own way and to its
own standards and specifications. This
situation created a dilemma for the
equipment owner; brand X wouldn’t
mate up with either brand Y or brand Z.
Pressure standards were virtually nonexistent as well. It was clear that, if the
valve industry was to take the next step
in its growth cycle, standardization was
needed. Stay tuned to the next column
in this series for the story of U.S. valve
standardization. VM
GREG JOHNSON is president of United Valve
( www.unitedvalve.com), Houston, and is a con-
tributing editor to Valve Magazine. He serves
as chairman of VMA’s Education & Training
Committee, is a member of the VMA
Communications Committee and is on the board
of the Manufacturers Standardization Society.
In 2010, Johnson was the recipient of VMA’s top
honor, the “Man of the Year” award. Reach him
at greg1950@unitedvalve.com.
