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4.1.6.2.2 Step 2: Retaining Ring & Bolting Installation
Attach and secure the retaining ring in place with the flange bolting hardware and
proceed to section 4.1.7 for flange bolt torqueing
Figure 27: Model RF-DBI-LH Flanged Installation Step 2
4.1.7
Flange Bolt Torqueing (Model RF-DBF/RF-DBI/RF-DBJ & Flanged RF-DBI-LH)
Torqueing should then be accomplished in steps gradually
and as evenly as possible around the circumference of the
flange. The bolts should be tightened in an alternating
sequence similar to a star pattern shown below in Figure 18
to within the proper torque range specified for the size of
check valve to be installed. The flange bolting is not
considered tight and “locked-on” until the edges of the check
valve flange bulges out or extrudes slightly. Refer to
appendix A for the proper ranges of torque values as well as
further examples of the proper patterns used for torqueing the
flange bolting.
Note: Never tighten bolts on a flanged rubber
check valve to the point where there is contact between the
retaining ring and mating flange. This type of tightening will
crush the integrated rubber flange of the check valve and
cause a premature failure.
4.1.8
Anchor Bolts/Pins (Model RF-DBO/RF-DBI-IN/RF-DBI-LH)
After the Check Valve is installed, drill a hole or holes, depending on the valve size number of clamps, through
the cuff of the check valve and into the mating pipe using the center hole on the clamp as a guide. Insert a bolt,
which will be sufficient in length to completely travel through the clamp, valve and mating pipe. Completely
weld or use some other means of ensuring that this bolt/pin will not fall out or be removed.
Figure 29: Model RF-DBO, RF-DBI-IN & RF-DBI-LH Typical Drilled Through Hole Positions
Figure 28: Sample Flange Torqueing
Sequence