Wall thickness of HDPE mortar tube

[pyrogenius007]

Hi, I have a HDPE pipe with an OD of 90mm and ID of 85 mm. The wall thickness is 2.5mm. I want to use this to launch my round shells which have a dia. of 80mm, the fuse is about 4mm thick, the whole assembly slides smoothly into the tube leaving a gap of about 1 mm. I want to use about 25grams of BP to propel the shell. My question is if the wall thickness is ok or should I go for a tube that has a thicker wall. I would like to add that in India we do not have dedicated pyro suppliers like in the US or other countries, we have to make our shells as per the tube sizes that are available which are mostly made for industrial, agriculture, water or sewer lines. I tried to search for information about ideal wall thickness for mortar tubes but did not come across it in the forum, if there is one please let me know. Thanks.

[cmjlab]

I can't speak to ideal wall thickness for pressure created by a lift charge, sorry.

 

I can help out with what my HDPE mortars are.

3" Mortars: HDPE DR17 (3" ID / 3.55" OD)

4" Mortars: HDPE DR21 (4" ID / 4.5" OD)

5" Mortars: HDPE DR21 (5" ID / 5.55" OD)

6" HDPE Mortars are DR21 as well with approximately 1/4" wall thickness.

 

In my 3" Shells I use approximately 36g for a ~1 lb to ~1.5 lb Cylinder Shell, with a close fit.

 

Hope that helps

[Arthur]

In the UK HDPE pipe tends to have thicker walls than that usually starting at 10mm wall thickness. However the PVC drain pipe tends to have a thinner wall and is unsuited for mortars because the plastic is brittle and may break. Be very sure that the pipe is HDPE or MDPE, preferably it should be marked Hdpe or MDPE on the side.