Roy Mundy, P.E., ENV SP, Assoc. DBIASenior Regional EngineerMcWane [email protected]
RESTRAINED JOINTS
Design Pressure – Maximum pressure line will be subjected to
Soil Structure – sand, silt, clay, etc, etc.
Laying Conditions – Depth of bury / Trench type
Vertical or Horizontal – deflection / bends / dead end
Polywrap – will require additional RJ pipe
Factors to take into consideration when restraining
Restrained JointsSure Stop 350® Gasket
• 3”- 24” Sizes• NSF-61 Approved• UL Listed • FM Approved• 350 psi Rated
GETTING STARTED WITH A BRIDGE CROSSING• Envision –Are we doing the right project?• –Are we doing the project right?• •Bridge Details: will be discussed in further detail later.• –Length• –Radius• –Local Temperatures• –Pipe Location on bridge• –Specific Pipe lengths• –Transition of line from bridge to underground
PIPES YOU COMMONLY SEE• TR Flex vs MJ & Flange pipe• -TR-Flex –more flexible.• -Improved gasket compression.• -Tyton10% compression required –20 to 30% average.• •MJ compression is based on bolt torque.• –TR –readily available.• –TR –Easier to install.• •No bolts / concerns for relaxing bolts –vibration.• -8” Tyton–1 minute to install.• -8” Mj–15 to 30 minutes to install.
Pipe location will determine the type of hangers required as well as spacing.
• Under the bridge Deck
• Through the Girders
• Side of the bridge
• One top of the bridge
• Supports must support weight of pipe and fluid: • 12” C350 • Gallons per 18’ length = 115 Gal.• 115 Gallons x 8.35 lbs per Gal. = 960 lbs• Pipe weight 35lbs per ft x 18’ = 630 lbs• Total weight = 1,590 lbs• Drilling / Anchoring in concrete –CAUTION
(Anchors are only as good as the connection)
• Supports should be placed as close to the bell on the bell side of the joint.
• May be necessary to provide cut pipe for the bridge crossing:
Example: Niagara Falls840 Feet of 24” pipeDual lineEach piece cut to specific lengthAll lengths marked on face of bellAll pipe joints and hangers matched
PIPES YOU COMMONLY SEE• TR Flex vs MJ & Flange pipe• -TR-Flex –more flexible.• -Improved gasket compression.• -Tyton10% compression required –20 to 30% average.• •MJ compression is based on bolt torque.• –TR –readily available.• –TR –Easier to install.• •No bolts / concerns for relaxing bolts –vibration.• -8” Tyton–1 minute to install.• -8” Mj–15 to 30 minutes to install.
TRANSITION From
Bridge to Underground
• Casing is often required through Abutment.• –ID of casing / OD of pipe bell.
(OD information: Submittal Sheets. mcwaneductile.com)• •TR vs MJ fittings• –MJ fittings are more common.• –MJ field cuts are common making the transition.• –TR Flex fittings –No thrust blocks required.• •Reduce angles whenever possible.
Other Considerations
• Insulation–regions with freezing temps.• Cable bond connections may be installed for electrical
thawing.(TR Flex® Joint restraint is not adequate for Electrical
Thawing or Cathodic Protection.)• A drain plug may be installed to drain lines which are
not in continuous service.• Air release may be required if the bridge crossing is at a
high point in the system.(Also for pressure testing the bridge section.)
Material Expansion Per 100’ per 10 Degrees
¾” ------------------------------------Ductile Iron Pipe
3.6”--------------------------------------------PVC Pipe
10.0”------------------------------------------HDPE Pipe
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