TM5-4930-230-13
(d.) Conduct a
combustible vapor test
combustible vapor test reading to determine if the tank is safe to repair. If
reading indicates tank is not safe, repeat procedure of subparagraph (C).
c. Inspection of the Tank Assembly.
(1) Check the tank for the condition of the paint.
(2) Check the tank for dents that require repairs. Check dents on welds for breaks in the weld seam.
Check for any damage or wear that has caused a rupture or leak.
(3) Check the interior of the tank for general cleanliness and the presence of contaminants.
WARNING
When using compressed air, wear safety goggles or glasses
and ensure air blast is not directed at another person.
Do not direct compressed air against the skin.
( 4 ) W h e n t e s t i n g t a n k,
completely dry and clean the interior and exterior
of the tank of all foreign matter.
When the tank is completely dry and clean,
c l o s e a l l o p e n i n g s s u c h a s v a l v e s a n d f i l l c a p , p l u g a n d f i l l c a p v e n t , a n d
subject the tank to a constant internal air pressure of 3 to 5 pounds per square
inch gage (PSIG).
Spray liquid detergent conforming to P-D-223 over the entire
e x t e r i o r s u r f a c e o f t h e t a n k a t a p r e s s u r e o f n o t l e s s t h a n 7 0 P S I G ( h a n d
sprayer).
A p p l y i n g t h e l i q u i d d e t e r g e n t b y b r u s h o r o t h e r m e a n s i s n o t
acceptable.
Observe the exterior of the tank.
Leaks as evidenced by fizzing
o r b u b b l i n g o f t h e l i q u i d d e t e r g e n t , s u r f a c e r u p t u r e , d e f o r m a t i o n , o r b r o k en
hardware shall constitute failure.
d. Repair of the Tank Assembly.
WARNING
If conditions require fuel tank repairs by welding or other methods
involving heat or flame, take care to assure that all fumes are purged from
the tank or fill tank with water before commencing the repair. possible,
tank should be filled with water prior to welding after being thoroughly
purged of fumes. Applying heater flame to a fuel tank containing residue
may result in a violent explosion, causing injury or death to personnel.
(1) Repair all dents, cracks, breaks, and holes in the tank. Weid ruptured weld seams and other
damage. Replace badly damaged parts.
WARNING
When using compressed air,
wear safety goggles or glasses
and ensure air blast is not directed at another person.
Do not direct compressed air against the skin.
( 2 ) N o r e p a i r w i l l b e i n i t i a t e d o n t h e t a n k u n t i l i t h a s b e e n t h o r o u g h ly
vented and cleaned.
Before attempting to do any welding repair on the tank,
d r i l l f o u r 1 - ½ i n.
dia. drain holes in each skid (total of 8 holes required).
F o r t h e l o c a t i o n o f d r i l l i n g p o i n t s , s e e f i g u r e 5 - 1 5.
Provide corrosion
protection to drilled holes and leave open.
If there is evidence of fuel inside
the skids when holes are drilled, purge the skids by steam cleaning or other
suitable method.
T e s t f o r l e a k s b y f i l l i n g t h e t a n k a p p r o x i m a t e l y ¼ f u l l of
water,
sealing all holes in skid except one and applying compressed air (not
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