4-68. PURGING TANK.
Chemical Purging (Alternate Method)
General Safety Instructions (Con't):
When working inside tank, always provide
adequate air ventilation at the manhole
opening with air directed into compartment
where work is being performed.
NEVER work alone inside a tank: a second
Tool kit, general mechanic's
person must be stationed at the manhole
opening. The person inside the tank must
have a safety line and harness on in case of
emergency for rescue operations.
In an emergency, personnel entering tank
which is not vapor free must wear an
attached lifeline and protective respiratory
equipment. Personnel MUST NOT enter a
tank which is in the explosive range.
Give IMMEDIATE medical attention to per-
sonnel exposed to hydrocarbon or toxic va-
Personnel engaged in draining and purging
operations must wear prescribed clothing.
Personnel Required: Three
Before climbing onto semitrailer, grasp
static ground wire to discharge all static
General Safety Instructions:
DO NOT perform draining or purging
If semitrailer is left overnight after purging,
operations in an electrical storm.
retest with combustible gas indicator set to
Connect bonding and grounding connec-
ensure a SAFE reading.
tion before beginning draining and purging
Compressed air used for drying tubing
operations. Maintain bonding and ground-
must not exceed 30 psi (207 kPa).
ing connection until after all draining and
purging is completed.
Keep open flames or other sources of
ignition away from area where draining or
purging operation is in progress. Sufficient
fire extinguishers MUST be present and
a. GENERAL INFORMATION
Removal of combustible vapors and liquids requires a coordinated effort of properly skilled
safety and maintenance personnel. This maintenance procedure is to be performed by
authorized unit or direct support personnel with an MOS of 77F or equivalent.
A thorough reading of FM 10-20 and TB 43-0212 is essential for understanding proper draining
and purging methods.