Pneumatic valve.
Check the valve position with reference to PID.
Check the availability of secure platform , operation flexibility
etc.
Consult manufacturer’s manual to know the detail of the valve
Check the basic characteristic of the valve whether it is air to
open /air to close.
Check the damage of the valve controller box and other small items
like air filter regulator ,
air lock relays ,small gauges connected with
controller box ,position transmitters ( if available) and
limit switches.
Study the system requirement of the valves in the process.
Check the power air supply ( 0 to 7Kg/cm2 ) and control air supply
( 0.2 to 1.0 Kg /cm2)
Check the function of EP (electro –pneumatic) controller before
mounting.
Check the cu-tube /ss –tube connection at different places by
charging air . Checking should be done by
soap solution. Control air piping to
be checked thoroughly as signal strength is less and can give
erroneous reading
during calibration.
Charge the air for commissioning. Test jig having ( 0.2 to 1.0
Kg/cm2) to be connected otherwise DCS
to charge for signal. Before charging of
air please flush the line well to remove dirt specially of
control air line.
Valve operation to be done
five to six times to set the open- close limit switches.
Check the valve in different position through control air supply jig. Calibrate the valve
with zero and
span . Calibrate the valve position transmitters.
Check the valve stay put condition on failure.
Check the manual operation of the valve ( if available)
Protocol all the checks and readings for future reference.
Keep the valve in close position.
Checking of Pipelines
:-
General checks
The installation is complete and correct in accordance with the
latest approved drawings and
specification.
Check that all bosses, flanges and tapping points have been
adequately made off.
Check that all cold pulls, if required, have been made and records
completed.
Check that all pipe falls to drainage points are satisfactory.
Confirm that all blanks still required in the system are
identified and recorded in the Blanks Schedule
Check that drains are provided at all points on the steam range
where water may collect.
Check that steam traps are fitted with bypass and test
connections.
Confirm that all pipework that can be touched from walkways etc,
and that reaches a temperature of 60
deg C or over is adequately lagged.
Check that adequate number of vents are provided on the pipe at
highest points.
Check that all supports are undamaged, fixed and mounted
vertically, (Except where design requires the support
at a specified angle).
Check that all support loadings have been correctly set and recorded.
Confirm, where possible, that there is a radial clearance between
the pipe and the support clip.
Check that all roller and sliding supports are clean, free to move
and so constructed that dirt and water
cannot accumulate.
Check that all thrust/anchor points are correctly installed.
Check that all the supports as required as per the drawing.
Flush the pipe line properly to open drain to clear of all debris
from pipe.
Test the pipeline hydraulically to the relevant standard in
presence of Boiler Inspector if required.
Check that all temporary supports have been withdrawn.
Confirm adequate support for small bore, horizontal pipes that may
be stood upon (or adequate
protection for the pipes and supports for system not
strong each to withstand additional loads).
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