# TPR Valve Discharge pipe **URL:** \ **Category:** Plumbing Inspections\ **Created:** [September 2, 2016, 6:52pm UTC](https://forum.nachi.org/t/tpr-valve-discharge-pipe/109248 "2016-09-02T18:52:52Z")\ **Posts on this page:** 14\ **Page:** 1
**Author:** ![aoneill](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/aoneill/32/173633_2.png) [@aoneill](https://forum.nachi.org/u/aoneill)\ **Post date:** [September 2, 2016, 6:52pm UTC](https://forum.nachi.org/t/tpr-valve-discharge-pipe/109248/1 "2016-09-02T18:52:52Z")
Good Afternoon, Been coming across several TPR discharge pipes that are very close, if not touching, the bottom of a water heater drip pan. What is the minimum distance from the bottom of the drip pan? Should’t there be some air gap? I understand the 6 inch rule for discharging to a waste receptacle but how close can the pipe be to the floor or drip pan? Thanks! Artie ---
**Author:** ![rcooke](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/rcooke/32/57038_2.png) [@rcooke](https://forum.nachi.org/u/rcooke)\ **Post date:** [September 2, 2016, 6:55pm UTC](https://forum.nachi.org/t/tpr-valve-discharge-pipe/109248/2 "2016-09-02T18:55:22Z")
Not good but I would say should be 6 inches but not make a big deal about it . What have you been saying with the several you have seen ---
**Author:** ![gmathias1](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/gmathias1/32/194308_2.png) [@gmathias1](https://forum.nachi.org/u/gmathias1)\ **Post date:** [September 2, 2016, 6:57pm UTC](https://forum.nachi.org/t/tpr-valve-discharge-pipe/109248/3 "2016-09-02T18:57:55Z")
I would have in the report that the TPR discharge pipe should be approximately 6" off the ground. I would verbally mention to the buyer that it is a simple fix requiring simple tools. ---
**Author:** ![aoneill](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/aoneill/32/173633_2.png) [@aoneill](https://forum.nachi.org/u/aoneill)\ **Post date:** [September 2, 2016, 7:07pm UTC](https://forum.nachi.org/t/tpr-valve-discharge-pipe/109248/4 "2016-09-02T19:07:30Z")
Thanks Roy! I have been telling the homeowner that the pipe needs to be cut to create an air gap and that the distance can be no bigger that 6 inches. The fact that I have seen this on several new homes and I couldn’t find anything in the Florida Building code that specified any change in policy, I figures I would ask the InterNACHI community for their thoughts. ---
**Author:** ![rcooke](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/rcooke/32/57038_2.png) [@rcooke](https://forum.nachi.org/u/rcooke)\ **Post date:** [September 2, 2016, 7:11pm UTC](https://forum.nachi.org/t/tpr-valve-discharge-pipe/109248/5 "2016-09-02T19:11:51Z")
> [@aoneill](#): > > Thanks Roy! > > I have been telling the homeowner that the pipe needs to be cut to create an air gap and that the distance can be no bigger that 6 inches. The fact that I have seen this on several new homes and I couldn’t find anything in the Florida Building code that specified any change in policy, I figures I would ask the InterNACHI community for their thoughts. > **[TPR Valves and Discharge Piping](https://www.nachi.org/tpr-valves-discharge-piping.htm?loadbetadesign=0)** ---
**Author:** ![jjonas](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/jjonas/32/301755_2.png) [@jjonas](https://forum.nachi.org/u/jjonas)\ **Post date:** [September 2, 2016, 7:31pm UTC](https://forum.nachi.org/t/tpr-valve-discharge-pipe/109248/6 "2016-09-02T19:31:19Z")
Minimum 3/4 inch Maximum 6 inches ---
**Author:** ![aoneill](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/aoneill/32/173633_2.png) [@aoneill](https://forum.nachi.org/u/aoneill)\ **Post date:** [September 2, 2016, 7:50pm UTC](https://forum.nachi.org/t/tpr-valve-discharge-pipe/109248/7 "2016-09-02T19:50:55Z")
Thanks Jeff…where is the 3/4 inch minimum written? ---
**Author:** ![jolson8](https://avatars.discourse-cdn.com/v4/letter/j/a88e57/32.png) [@jolson8](https://forum.nachi.org/u/jolson8)\ **Post date:** [September 2, 2016, 7:54pm UTC](https://forum.nachi.org/t/tpr-valve-discharge-pipe/109248/8 "2016-09-02T19:54:51Z")
3/4 " is minimum size of the discharge pipe ---
**Author:** ![rcooke](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/rcooke/32/57038_2.png) [@rcooke](https://forum.nachi.org/u/rcooke)\ **Post date:** [September 2, 2016, 7:58pm UTC](https://forum.nachi.org/t/tpr-valve-discharge-pipe/109248/9 "2016-09-02T19:58:00Z")
> [@jolson8](#): > > 3/4 " is minimum size of the discharge pipe And What do you do when the tank has a 1/2 pipe on a 1/2 tpr ---
**Author:** ![jjonas](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/jjonas/32/301755_2.png) [@jjonas](https://forum.nachi.org/u/jjonas)\ **Post date:** [September 2, 2016, 8:11pm UTC](https://forum.nachi.org/t/tpr-valve-discharge-pipe/109248/10 "2016-09-02T20:11:49Z")
> [@jolson8](#): > > 3/4 " is minimum size of the discharge pipe Exactly. So logic dictates that the air gap should also be no smaller than the discharge pipe size. ---
**Author:** ![jolson8](https://avatars.discourse-cdn.com/v4/letter/j/a88e57/32.png) [@jolson8](https://forum.nachi.org/u/jolson8)\ **Post date:** [September 3, 2016, 12:37pm UTC](https://forum.nachi.org/t/tpr-valve-discharge-pipe/109248/11 "2016-09-03T12:37:10Z")
not be smaller than the diameter of the outlet of the valve it serves (usually no smaller than 3/4"). ---
**Author:** ![jolson8](https://avatars.discourse-cdn.com/v4/letter/j/a88e57/32.png) [@jolson8](https://forum.nachi.org/u/jolson8)\ **Post date:** [September 3, 2016, 12:45pm UTC](https://forum.nachi.org/t/tpr-valve-discharge-pipe/109248/12 "2016-09-03T12:45:48Z")
> **[Code Ref for TPR valve piping?](https://forum.nachi.org/t/7664)** > > Hi again. Does anyone have a UPC code reference for approved piping material for TPR valve piping? It is my understanding that PVC does not meet the minimum temperature requirements and that CPVC does. Quick glance netted nothing in the IRC. Thanks ---
**Author:** ![jjonas](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/jjonas/32/301755_2.png) [@jjonas](https://forum.nachi.org/u/jjonas)\ **Post date:** [September 3, 2016, 12:54pm UTC](https://forum.nachi.org/t/tpr-valve-discharge-pipe/109248/13 "2016-09-03T12:54:15Z")
> [@jolson8](#): > > [Code Ref for TPR valve piping? - Plumbing Inspections - InterNACHI®️ Forum](https://www.nachi.org/forum/f22/code-ref-tpr-valve-piping-8003/) Be sure to note in this (old, so may no longer apply) link that the codes referenced are for California and with EXTERIOR discharge points (6in to 24in). ---
**Author:** ![jolson8](https://avatars.discourse-cdn.com/v4/letter/j/a88e57/32.png) [@jolson8](https://forum.nachi.org/u/jolson8)\ **Post date:** [September 3, 2016, 1:04pm UTC](https://forum.nachi.org/t/tpr-valve-discharge-pipe/109248/14 "2016-09-03T13:04:31Z")
This is the code in Wisconsin. The outlet of the discharge pipe shall terminate within 6" over the floor or receptor, but not less than a distance equal to twice the diameter of the outlet pipe. The outlet of the discharge pipe may not be threaded.