To determine spacing between 150 nb pipe of 150 rating and a 100 nb pipe of 600 rating.
Pipe against roof distance between math.
B to determine the pipe slope subtract the two manhole inverts and divide the difference by the pipe distance and multiply by one hundred 100 to obtain the percent grade of the pipe.
And for gas service 17 ft for 2 to 40 ft for 8.
Any blockage or restrictions in the system may result in water backing onto or under the roof membrane.
304 4 300 the pipe distance between manholes will be 300 feet but a distance of 304 feet should be shown on the profile.
The restriction must be protected against frost damage due to the cold helium gases.
If the distance between the outlet and any restriction e g.
For example a common pitch like 4 12 would mean that for every 12 inches of run the roof rises 4 inches.
If you want to make a bend on a 4 5 radius die and you want that bend to be 10 inches from the end of a piece of tube mark a line on the tube 10 inches from the end.
For 150 nb pipe and 100 nb 600 flange rating spacing 255 mm.
All open vent pipes that extend through a roof shall be terminated at least number typically 6 inches mm above the roof except that where a roof is to be used for any purpose other than weather protection the vent extensions shall be run at least 7 feet 2134 mm above the roof.
The bend offset is the distance between the start of the bend and where you line up the tube in the machine.
The 18 number comes from the horizontal distance allowed between a verticle run of pipe and a verticle combustible wall surface.
The roof or wall is between 100 cm and 300 cm.
Spacing half od of a flange which is larger between two pipes half od of other pipe insulation thickness of both pipes 25 mm or 1 inch.
Now for the math lesson.
Roof pitch is expressed as a ratio of rise over run.
See the image below.
Things change significantly when you re talking about clearence from the single wall to ceiling in the case you re referring to.
The span is 4 ft for pipe up to 6 ft for 4 schedule 40 pipe at ambient temperature.
Horizontal pipe capacity must be checked as part of an adequate design.
In such case for economic reasons clamped pipe supports at an angle of 45 degrees should be used.
Spacing between pipes on a pipe rack larger spacing may be required if pipes have clamped supports.
For fiber reinforced plastic pipe frp support spacing in liquid service would vary from around 11 ft for 2 pipe to 22 ft for 8 pipe.
When placing roof drains it is good design practice to locate the drains no more than 50 feet from the roof perimeter nor more than 100feet apart.