Velan Design - Velan Bimetallic
QUICK STARTS – SUPER CAPACITY AIR VENTING
Discharge valve is wide open, allowing air and cold water to pass quickly. The
hours of waiting in the morning for equipment to warm up are reduced to minutes. It
is certain that no air-binding, water-logging or steam-locking will slow the
heating up. Actual tests show that up to 2 ½ hours may be saved
on each warm-up time of equipment due to 4-6 times greater venting capacity than
average traps, due to the oversized orifice of ½ or 5/8 in universal traps,
7/8 in super traps and 2” in “piston” traps.
STEAM TRAPPING
Incoming steam contracting the bimetallic element causes the bimetal to deflect
and develops a thermal power of the bimetal acting on the valve stem, which
overcomes the steam pressure and closes the valve. This thermal pull
seats the ball valve tightly in its seat, preventing dribbling and loss of
live steam. This thermal power increases or decreases as a function of
temperature in the same relation, as temperature and pressure of saturated
steam. The same element can be used for varying steam pressures within
the range of 0-350 psi.
…ACTUAL TESTS PROVE THAT VELAN TWO-STEP STEAM TRAPS MORE THAN DOUBLE
THE DRAINAGE CAPACITY OF ORDINARY THERMOSTATIC STEAM TRAPS
When cooler condensate and air collects in the trap, the thermal pull of
the bimetal is gradually reduced until the line pressure can overcome the thermal
pull and the unbalanced pressure on the valve cracks the orifice and releases
the flow of condensate.
- This is the first step of the smooth and quick opening of the valve avoiding
the noisy and violent opening of ordinary steam traps.
- When flow is released the unbalanced pressure acts now on the full valve
area doubling its force to overcome the thermal pull and opens the orifice
widely for full capacity. The ½, 5/8, 7/8 orifice in Velan steam
traps is 2-6 times larger than in traps of equal size.
DOUBLE DRAINAGE CAPACITY
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100% BACK-FLOW CONTROL
Back pressure in return line, sudden drop in steam pressure, rapid fluctuation
or discharging to overhead lines causes back-flow of condensate. To prevent
this possible back flow or entering of condensate into equipment not
in service separate check valves should be installed as close to the steam
trap as possible. In
the unique design of the Velan steam traps the same discharge valve acts
as check valve providing 100% back flow control.