This will allow air flow to continue when two compartments drain simultaneously. If the use of 90 degree bends is necessary, consider using long sweep 90 degree bends.In running excessively long lines for drainage, one of the most common problems is blockages occur as the drain line remains the same diameter throughout the distance of the drain line. Gravity will lead water down from the branch of the tee. If we maintain our pitch and increase the pipe size, adding clean outs (keeping them accessible) we can maintain these long lines. In order to give the pipe proper pitch, the pipe needs to be routed to an outside wall, while remaining in the joist, at 1/4″ per foot pitch. The answer is, the vent is choked off, water stops flowing until the air inside the pipe can vent it. Using 2 – 45 degree bends will allow a longer turn radius. The total linear footage for the kitchen drain line was approximately 75 feet.This kitchen sink drain diagram illustrates inefficient piping. What eventually occurs is occlusion. Here, we see a kitchen sink drain line having excessive bends and length of pipe in the composition of the drain line. However, the ventilation is lost as soon as the waste water piles in the 90 degree bend after dropping from the tee. But, then there is a second horizontal drop where the water meets another 90 bend.

Proper installation of the plumbing system will determine problems or efficiency in the use of the drain. The pipe will eventually lose its vent line as the pipe fills with debris. In the diagram above, the vertical pipe from the tee leads down to a 90 degree bend. And, air will flow in from above the tee, through the sewer or plumbing vent. Following the drop, there is a third 90 degree bend then the pipe is horizontal until it runs over to the stack and meets a 45 degree bend and then drops into the sewer. What occurs is, the grey water from the kitchen sink becomes vented when it drops through the branch of the tee. Your drainage line should be 11/2″ to 2″ diameter, depending on the use.You may be wondering why the 90 degree bends are a problem.

If you are piping a bathroom sink drain, you can reliably use 11/2″ drain pipe to discharge water from the sink to the sewer.Drain Vent And WastePosted by anchorseweranddraincleaning on August 8th, 2017The following diagram illustrates problems had with improper drain systems.The use of 90 degree bends should be avoided where possible. Where possible, use 45 degree bends to move the sewage through vertical to horizontal transitions.)Length of the drain line (Again, this problem may not be avoidable)Inside diameter of the pipe for the applicationPoor ventingFrom the kitchen sink, the piping generally disappears into the wall behind the cabinet. Also, we have the ability to monitor the flow in the line with clean outs. Also, determine the amount of volume that will pass from the sink. The piping will run horizontally to a tee.Too many elbows (This diagram illustrates 7 bends, not including the trap.The following video is taken from a project we were involved tail pulley manufacturers in, to re-pipe a drain line