MODCO FIGURE 500 Installation Instructions Manual page 8

Opening the Figure 500 Closure
a. Make certain all pressure has been safely bled from the vessel or pipeline. Attempting to open
a closure without doing so could lead to a violent expulsion of pressure resulting in injury or
death.
b. Remove the Pressure Alert Valve (PAV) stem, if so equipped, and screw it into the retainer on
the cap. The PAV is used to alert the operator of residual pressure in the vessel or pipeline.
Unrelieved pressure can cause severe injury or death. If residual pressure is indicated, replace
the PAV stem and ensure the vessel or pipeline is bled of all pressure. Do NOT use the PAV to
bleed pressure from the vessel.
NOTE: The Pressure Alert Valve (PIC #1) is
standard on all 6 inch and larger closures. The
PAV may not be present on two, three, or four-
inch closures as it is an option on these sizes
on non ASME code stamp closure.
c. Check for reference marks indicating the closed position of the cap and hub (PIC#2&3). If none
are present, make a temporary mark across the cap and hub (PIC#4), then follow the instruction
in the "First Time Start Up" section of this manual.
d. Rotate the cap counterclockwise with the lug wrench or ratchet tool provided (PIC#5&#7). Do
not use a hammer to open the cap. Hammering will deform the lugs on the cap and possibly
lead to cracking in the cap or injuries.
e. Rotate the cap until it is free of the hub. Then swing the cap to the side to gain access to the
vessel or pipeline.
IMPORTANT: For the safety of the operator and other crew members, stand to the side of the
closure when opening the cap. Do not stand directly in front of the closure when opening (PIC#6
wrong & PIC#7 correct).
Closing the Figure 500 Closure
a. Align the cap to the hub and rotate clockwise. Tighten the cap with a lug wrench or ratchet tool
until your reference marks line up (PIC#2,3&4). The reference marks indicate a metal to metal
contact of the cap and hub sealing surface.
b. On closures with a PAV, replace and tighten the PAV stem into the PAV body hand tight. Do not
use tools to
IMPORTANT: The cap will tighten sufficiently with the included lug wrench or ratchet
tool. Overtightening the cap will result in damage to the threads and sealing surfaces
of the cap. Do not use a hammer to tighten the closure.
Modco Standard (6.17.2019 - Q.C.) (Revision 1)
Part 1: Operation Instructions
tighten the PAV,
PIC #1
damage to the PAV may result.
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