Gasket Installation Guide for Firetubes.
83075 NRGMAX / Durlon® 8500 Page 1
Phone: 403-945-3561
Email: [email protected]
Website: www.nrgps.ca
Gasket Installation Guide for Firetubes.
83075 NRGMAX / Durlon® 8500 Page 2
What you need
- Durlon 8500 Gasket - Torque Wrench - 64 Stainless Steel Washers - Caliper (See note 8 on page 3)
- “Never –seize” (molybdenum disulfide) type Lubricant for bolts/nuts. (Not to be used on flange or gasket face)
Important things to know.
- Lubricant to be used on the nuts with the washers.
Bolt lubrication greatly affects the torque values used
when installing gaskets. To achieve the same gasket
compression, a much higher torque value is required for
a dry bolt versus using an effective lubricant such as
molybdenum disulfide. In a dry bolt up, or where an
inefficient lubricant is used, the effort used in tightening
is overcome by the frictional forces between the bolts
and nuts and to a greater extent; between the nuts and
nut facing. This can result in a lower gasket load and in-
adequate stress on the bolts, which can result in torque
loss and eventual leakage in service.
- Lubricant should not be applied to the gasket or flange
faces.
- S.S washers to be installed on the nuts facing the burner
housing. These are installed to reduce friction.
- It is recommended to replace any rusted or damaged
bolts/nuts/washers, to achieve a good seal.
- Bolt tightening sequence on in this manual should be
followed.
S.S Washer Side
Check List
Unit # / Project: __________________________ Install Technician: ___________________
Date Installed: ____________ Nominal Bolt Size: ______ Lubricant Used:_____________
Gasket Installation Guide for Firetubes.
83075 NRGMAX / Durlon® 8500
Page 3
(Initial each step)
_____ 1. Be sure system is at ambient temperature and depressurized. Follow local safety procedures.
_____ 2. Visually examine and clean flanges, bolts, nuts and washers. Replace components if necessary.
_____ 3. Install washers on outside (burner housing) side of flange.
_____ 4. Number Bolts in cross-pattern sequence according to sketch on next page.
_____ 5. IMPORTANT! Hand tighten; then pre-tighten bolts to 10/20 lbs torque, but do not exceed 20% of
Target Torque (first round torque value).
_____ 6. Check gap for uniformity.
_____ 7. Use appropriate cross-pattern tightening sequence in the sketch on the next page for rounds
1, 2 and 3.
Round (see note 8) Lubricated Bolts / Nuts
Round 1 111 ft-lbs (30% of final)
Round 2 222 ft-lbs (60% of final)
Round 3 370 ft-lbs
Final Rotational Round
(See note 9 Below)
370 ft-lbs
_____ 8. Check gap around the circumference between each of these rounds, measured at every other
bolt. If the gap is not reasonably uniform around the circumference, make the appropriate
adjustments by selective bolt tightening before proceeding.
_____ 9. Final Rotational Round: 100% of final torque (same as round 3). Use ROTATIONAL clockwise
tightening sequence, starting with Bolt No 1, for one complete round and continue until no
further nut rotation occurs at 100% of the final Torque Value for any nut.
_____ 10. Short-term bolt preload loss can occur between four to twenty four hours after initial tightening
due to bolt relaxation. Consider retightening to help recover this loss.
_____ 11. Retighten within a week of initial burner start up.
Tightening Sequence
Gasket Installation Guide for Firetubes.
83075 NRGMAX / Durlon® 8500 Page 4
Any Questions please contact us.
Gasket Installation Guide for Firetubes.
83075 NRGMAX / Durlon® 8500 Page 5
Phone: 403-945-3561
Email: [email protected]
Website: www.nrgps.ca
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