The specs are for a maximum pressure at a specified temperature, usually
72 degrees F. PVC softens with temperature so the ratings degrade with
temperature. It is usually not used for hot water service. The specs
say "Not rated for 140 degrees F".
One experience is that sch 40 fittings were the failure item in a 32
home water system I worked on. There were no sch 40 pipe failures. So
when a fitting failed we replaced it with a sch 80.
The specs also say "Warning: Never use plastic pipe fittings and pipe
with compressed air or gas."
Grant KZ1W
On 8/31/2019 11:06 PM, David G4FTC wrote:
Thanks for the data on the sch 80 pipe - I assume that the 300+ psi figures are
working pressures which should give a good margin.
It was the thought of having shards of PVC embedded in your body after a
catastrophic failure that scared me
David G4FTC
________________________________
From: Topband <topband-bounces@contesting.com> on behalf of Grant Saviers
<grants2@pacbell.net>
Sent: 01 September 2019 00:13
To: Topband@contesting.com <Topband@contesting.com>
Subject: Re: Topband: Drones for antenna installation?
I stick to max 80psi which has a good safety factor vs the pipe rating
(4" @220psi in my launcher). Very cold weather and knocking it around
when brittle or anytime is certainly to be avoided. An alternative is
to buy schedule 80, McMaster sells sch 80 PVC in 5 foot lengths. The
pressure rating for 3" is 370psi and 4" 320psi. Then the end fittings
should also be sch 80.
A friend once (young = stupid) made a firecracker out PVC pipe. Note
that PVC doesn't show on xrays, so small bits were still erupting from
his skin 20 years later. Fortunately no eye damage.
Grant KZ1W
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