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45 Cards in this Set

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what should be done if previous records indicate that because of continued deterioration, the thickness of a pipe will drop below the required minimum for safe operation?
replace the piping (pipe, valve, fittings)
what should be done with piping thinkess inspection reports?
they will be maintained by the ship for comparison purposes
what material and thickness should replacements for piping systems be?
replacements shall be of the same material and thickness as originaly installed
minimum wall thickness is calculated using what formula?
Tm=(PD)[2(S+YP)]
what is PRESSURE VESSEL PIPING?
the piping from the pressure vessel drum or header up to and including the first valve off the pressure vessel drum or header
what is the PRESSURE VESSEL PIPING referred to as?
the BOILER BLOW STOP VALVE
what is BLOWDOWN PIPING?
the piping from the outlet flange connectionsof the boiler blow stop valves to the outlet flange of the overboard discharge stop valve
what is DISCHARGE PIPING?
the piping from the flange connections of the overboard discharge valve outlet to the skin of the ship
piping replacement should be done before how many months from the date of inspection?
should be done at the next availability, but in no case more than 12 months from the date of inspection, when wall thickness is equal to or less than that specified in table 505-1-4.
piping must be replaced before what?
must be replaced before pressurizing boiler blowding piping if wall thickness is equal to or less than that specified in table 505-1-5
replaced sections of piping shall be what?
schedule 80 minimum and extend from nozzle to valve for pressure vessel piping and from fitting to fitting for blowdown and discharge piping
what material shall piping replacement be composed of?
shall be same as currently installed, CARBON STEEL or NICKEL COPPER
when may a sectional replacement be made?
in an emergency, when complete replacement of a piping run cannot be accomplished due to lack of material or lack of sufficent time
what is a SECTIONAL REPLACEMENT?
one in which the replaced section of piping does not extend from component to component.
what does component to component refer to when dealing with piping?
the boiler (boiler blow stop valve) to the sea chest
temporary sectional replacements can be made using pipe or tube having different material, size, and/or wall thickness requirements from existing piping.

TRUE OR FALSE?
TRUE. however, pipe or tube shall be suitable for use at the existing system pressure and temperature.
discharge piping replacement is composed of what?>
NICKEL COPPER per MIL-T-1368, class A, schedule 80 minimum. FLANGED NICKEL COPPER valves shall be used
what should you do if flanged nickel copper valves cannot be obtained?
refurbish and reuse the existing carbon steel overboard, stop-check, and guarding valves until nickel copper ones are obtained. flanges and fittings shall be nickel copper per QQ-N-281, nickel copper alloy bar, rod, plate, sheet, strip, wire, forgings, and structural and special shaped sections.
what type of flanges shall be used?
SOCKET or BUTT WELDED
BIMETALLIC piping shall be joined by what?
FLANGES. do not use BIMETALLIC WELDS.
what shall be used IN all flanges?
SPIRAL-WOUNDS GASKETS, GASKETS, METALLIC-FLEXIBLE GRAPHITE, SPIRAL WOUND and nickel copper fasteners shall be used in all flanges
what does MAIN PROPULSION BOILER SOOT BLOWER PIPING consist of?
consists of all piping located between the soot blower steam inlet (root) valve and the soot blower heads, including all drain lines,
high pressure drain piping is from what source?
the source of drainage on the steam system up to the cutout valve downstream of the steam trap (or orifice).
in an emergency, when a complete replacement of piping run cannot be accomplished due to lack of material or lack of sufficient time, is it allowable for a sectional replacement to be made?
yes, a sectional replacement may be made. the replaced section of piping will not extend from component to component. make the replacement section the same size and material as existing piping.
when shall you not perform a sectional replacement?
if piping of equal thickness to the originally installed material is not available.
what steel pipe bends should be used in a complete system replacement?
carbon steel pipe bends of five diameters shall be used in complete system replacements.
if space limitations during a complete system replacement require a tighter bend of steel pipe, what should be used?
a three-diameter bend radius.
with HYDRAULIC TRANSIENTS, why should valves be closed slowly?
because sudden stoppage or changes in the velocity and direction of fluids contained in piping systems will generate high pressures that may damage equipment.
why should you not start pumps with their discharge valves fully open, when the downstream piping is empty?
because thsi avoids high pressure transients that can damage piping and equipment.
what actions can minimize piping stresses?
closing valves slowly, draining condensate from stream lines before admitting steam, maintaining check valve vacuum breakers in proper operating condition, maintaining hydraulic and pneumatic valve operators to control valve opening and closign rates at specified values.
what is WATERHAMMER in service steam systems?
characterized by a loud metallic pounding noise.
what can cause water hammer?
inadequate drainage of condensate or heating the piping too rapidly.
where is the material in copper piping weakest?
in the vicinity of silver-brazed joints, due to annealing during fabrication.
water hammer stress added to normal pressure stress causes what?
produces a bulge in the annealed section. bulging may cause piping to become work-hardened, possibly reducing the chance for further bulging.
what should piping not be used for to avoid strain?
do not use piping as handholds, footholds, or to support weights. applies also to voice tubes, pneumatic tube dispatch piping, and other similar piping.
should cross connects between side tanks be kept shut?
yes. the list of a ship will be increased by transfer of fluids through open cross connections.
what fuel tank sounding tubes are floating ball check valves installed in?
installed in fuel, JP-5, and oily waste tank sounding tubes.
what kind of tanks do not require floating ball check valves?
lube oil tanks
what should be done to secured systems, components, and auxiliary equipment and its piping if freezing temperatures occur and such pipings are not protected?
they should be completely drained. if necessary, break drain connections to prevent damage due to freezing.
when may systems be cross connected?
for economy of operation during cruising, or for emergency operation due to equipment casualty or battle damage
all steam systems are designed for temperatures above what?
77F (fossil fueled ships). main steam system design presure (nuclear power ships) will require level-1 (material control standard) fasteners.
what type of fastener can easily be mistaken for steel and should not be used?
BLACK OXIDE coated brass.
steam for auxiliary service is taken directly from where?
the boiler drum internal desuperheater
what is installed for where the steam temperature has to be reduced because of limitartions of the service?
IN LINE DESUPERHEATERS. installed in conjunction with each pressure-reducing station. some are provided with high temp alarms.
why should all valve body drains be left open throughout the warm up period?
to permit drainage