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- PHUC Bell Info file #1 (Manholes)
- information obtained and typed by spota
- PHUC is:
-
- Piz Zart
- Krazihorz
- Spota
-
-
- This file is an excerpt from the Bell issued manual "BSAPP Key Point
- Reference Book #6" it is subject number 23, questions 145-155, which
- are on pages 51-54 of the actual manual..
-
- ----Begin
-
-
- MANHOLES
-
- References - BSP 081-310-103 Manhole tent
- BSP 081-700-100, 105, 106, 107, 110, 120, 122
- Gas Indicators
- BSP 620-140-501 Testing and Ventilating Manholes
- BSP 620-140-010 Petroleum Products in Underground
- BSP 620-150-010 Placing and Removing Manhole Covers
-
-
- D 145. What do you do prior to the opening of a manhole?
-
- -Place work area protection devices
-
- DE 146. How do you test the operation of a gas indicator?
-
- NOTE: Failure to pass any of the below tests requires
- replacement of the meter or parts thereof. Do not
- enter a manhole with a defective meter.
-
- -Test the battery by sqeezing the aspirator bulb five
- times to clear residual gas and zero in the indicator
- within the limits prescribed by the manufacturer.
-
- -Using a gas test kit allow the gas to enter the meter
- per instructions.
-
- -The indicator should register readings as prescribed by
- the manufacturer.
-
- -Test for tightness by squeezing the aspirator bulb.
- After releasing the bulb should inflate within five
- seconds.
-
- 147. When do you test for gas in a manhole?
-
- -Immediately after removing the manhole cover.
-
- -After purging and entering a manhole
-
- -A minimum of every two hours after making initial tests.
-
- -A minimum of one hour if manhole tent is used.
-
- -When opening a duct.
-
- -After removal of water from a manhole
-
- -At every shift change.
-
- 148. How do you remove a manhole cover?
-
- -One person can remove the cover by placing the feet
- solidly clear of the cover bending the knees and
- keeping the back straight.
-
- -Two persons should first both use their hooks on the
- same side to break the manhole cover seal. One person
- then moves to the opposite side of the cover and lifts
- and assists while the other person pulls.
-
- -Frozen manhole covers should never be thawed with an
- open flame. Covers can be loosened with a digging bar
- , hammer or chisel, or by directing a ventilating
- heater hose at the cover.
-
-
- 149. How do you test manhole atmosphere?
-
- -Lower the free end of the indicator hose to the point
- where a person's head will be when working in the
- manhole.
-
- -If sufficient water is present in the manhole to require
- pumping, hold the sampling hose one foot above the water
-
- -Draw a sample of the atmosphere through the gas
- indicator by compressing and releasing the aspirator
- bulb five times plus one squeeze for each five feet of
- sampling hose.
-
- -Observe the meter pointer continuously from the first
- squeeze of the bulb until the test is completed.
-
- -If the meter point moves rapidly to the top of the
- scale then returns to a point above zero, a heavy
- concentration of gas is indicated.
-
- E 150. What do the different indicator readings mean?
-
- -A near full scale or full scale movement of the
- indicator indicates an explosive level of gas.
-
- -A indicator reading over 1.0 or 100% requires purging
- and retesting with the blower in operation. If a second
- test still reads .1 to 1.0 or 10% to 100% do not enter
- and notify the supervisor
-
- -An indicator reading below 0.1 or 10% indicates that the
- manhole may be entered after purging.
-
- E 151. What do you do if gasoline fumes are smelled?
-
- -Use a gas indicator and a crushed inhibitor filter (if
- required for your indicator) to determine if the
- atmosphere is safe to work in.
-
- -Notify your supervisor immediately if required.
-
-
- E 152. Why must a manhole be purged?
-
-
- -No manhole should ever be entered unless the manhole is
- purged for the required time to dissipate any stagnant
- gas, ensure against oxygen deficiency and provide a
- complete air change in the manhole.
-
- -The purging time requirements can be found in BSP
- 620-140-501
-
- -Only one 90(degree) bend in the blower hose is permitted
- while purging.
-
-
- DE 153. Where do you locate the ventilating equipment?
-
- -The blower intake must be away from exhaust fumes.
-
- -The propane source should be in a secured upright
- position away from the blower intake and if possible
- lower than the manhole opening.
-
- -Only two 90(degree) bends are permitted in the blower
- hose ands the end must be secured in a horizontal
- position directed toward the end wall of the manhole.
-
-
- D 154. How do you enter a manhole?
-
- -Facing traffic and maintaining three points of contact.
-
- -Use only an appropriate ladder whose first step is no
- more than one foot below the ground surface.
-
-
- D 155. What additional tests are required after entry?
-
- -Duct entrances, corners and generally throughout the
- manhole.
-
-
-
-
-
-
- --------------End
-
-
-
- Alright guys.. thanks.. i Don't know how useful this information it
- is but remember, information is power.
-
-
- -Spota
-
- spota%tacobel@merk.com
-
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