25
Gas Valve Regulator Adjustment
Adjustment of the built-in regulator isn’t normally
necessary, since it is preset at the factory. However,
field adjustment may be accomplished as follows:
1. Attach manometer at pressure tap port.
2. Remove regulator adjustment screw cap.
3. With a small screwdriver, rotate the adjustment
screw clockwise to increase or counterclockwise to
decrease gas pressure.
4. Replace regulator adjustment screw cap
(As Shown).
Pressure Relief Valve
Each machine is equipped with a relief valve to relieve
pressure in the system when higher than normal
operating pressures are encountered. If operating
pressure of machine is found to be normal and relief
valve continues to leak, repair or replace the valve.
CAUTION: Relief valve can become obstructed by
deposits and must be unscrewed at least once per
year to allow discharge.
ATTENTION: La soupape de décharge peut devenir
obstruée par des dépôts et doit être dévissée au
moins une fois par année pour permettre le rejet.
Propane Gas
General Safety Precautions
Have a qualified gas service person assist in any gas
burner installation or service. Few maintenance people
or mechanics are knowledgeable in gas controls or
related safety practices. Propane gas is heavier than
air; unburned propane gas will gravitate to the floor
rather than rise out of the stack. Hence, adequate floor
space and good ventilation are especially important
with propane systems.
Gas Pressure Requirements
All propane fired machines operate on vapor propane
fuel only. They are designed to operate at a pressure of
11 w.c.i. (between 1/3 and 1/2 of one psi), and are often
operated at even higher pressures when extra heat is
needed.
Exterior regulators are needed to control the system.
Propane bottles are not included with the machine. A
high pressure regulator should be installed on the
propane bottle and a low pressure regulator attached to
the pressure washer.
Propane Cylinder Capacity
An important consideration with propane systems is the
capacity of the supply cylinder relative to the needs of
the burner. The burner operates on propane as a vapor
gas. As gas is used from the propane cylinder, the
liquid in the cylinder boils to maintain vapor gas
pressure. This boiling process cools the liquid, and in a
heavy, continuous-demand situation, the liquid
temperature can fall to the point at which it cannot
provide vapor gas as rapidly as is needed. In this case,
it may be necessary to warm the propane cylinder by
directing a warm spray, not over 120°F, on the cold
cylinder or by manifolding two propane bottles together
to increase total vaporization capacity. It is recom-
mended that a minimum 100 lb. vapor propane bottle
be used on the machine, depending on the length of
running time desired.
Landa VHG Operator’s Manual 8.913-952.0 - BR
