In case tightening or loose-
ning the clamps of manhole
cover when the tank is under
pressure, manhole cover may
break off from tank body and
may result in injuries even
death. Never tighten or loosen
the clamps of the manhole co-
ver, when the tank is under
pressure.
If the threads of hatch clamps
are damaged, manhole cover
may break off from its body
and may result in injuries
even death.
•
Tank must not be under pressure
even a single thread is damaged.
•
Always tighten the levers manually.
•
Replace immediately damaged
threads.
Damaged thread of the hatch
clamp cannot withstand inner
pressure of tank and will be
broken.
Consider the following subjects dur-
ing
opening
or
closing
manhole
cover:
•
Check the contact surfaces of man-
hole cover are clean and non dam-
aged before closing.
•
After closing manhole covers, tight-
en hatch clamps crosswise and
manually.
•
Never tighten the hatch clamps with
your foot, with a pipe, hammer or
any other tool.
•
Never retighten or loosen the hatch
clamps of manhole cover when the
tank is under pressure.
•
Grease threads of hatch clamps
regularly.
4.2.5. Pressure Safety Valve
Pressure safety valve (1) is an important
protective equipment. It prevents the ex-
plosion of the tank by keeping the pres-
sure (operating pressure) in the tank
constant at the set value during pressur-
ized discharge. Pressure safety valve is
located on the front part of the vehicle,
on the side air line.
Pressure safety valve
4.2.6. Vacuum Valve
Vacuum valve (1) is an important protec-
tive equipment. Prevents negative pres-
sure that may be generated by the
variations on air pressure and tempera-
ture inside the tank. Protects against
damage of tank due to pressure. As a
standard, vacuum valve is located inside
the spill box.
Vacuum valve
