[K3CAL] Regarding the PVC used in the antenna launcher

[N3QHC]

Hi Ed, 

Not sure of your source of 200 psi.  If from the people that makes these
launcher's then I would be concerned.  I might be stated as such for
promotional purposes.  I rather rely on engineering specs.  Having a device
explode next to one's body is not going to have very good results!

 There are other factors that determine if PVC is 'good' at a certain
pressure such as TEMPERATURE.  See
http://www.engineeringtoolbox.com/pvc-cpvc-pipes-pressures-d_796.html .
Notice max pressure for PVC is 166 psi but at 73-d F the pressure is reduced
by 20% or 132 psi.  Consider having a launcher in a hot car during the
summer and getting it out to launch a tennis ball.  The max pressure is .3 x
166 psi at 130-d F or about 60 psi max.  Source:
http://www.engineeringtoolbox.com/thermoplastic-pipes-temperature-strength-d
_794.html 

Notice that CPVC has higher max psi than PVC.  This why PVC is illegal to
use in house plumbing for hot water.  CPVC is legal for hot water plumbing
in homes.  

Just because someone makes these launchers does not make them safe to use. 

73, Dennis N3QHC 

-----Original Message-----
From: k3cal-bounces at mailman.qth.net [mailto:k3cal-bounces at mailman.qth.net]
On Behalf Of Edwin A Noell Jr
Sent: Friday, September 20, 2013 10:42 PM
To: Calvert Amateur Radio Association - K3CAL
Subject: [K3CAL] Regarding the PVC used in the antenna launcher

Guys:

If you read the specifications on the antenna launcher, you'll find that the
launcher is made with SDR21 PVC.

This PVC is good for a pressure of 200 psi, which is well beyond the working
pressures of 70-80 psi used in the launcher.

However, thank you for the warning.

Ed, KC3AEN
______________________________________________________________
K3CAL mailing list
Home: http://mailman.qth.net/mailman/listinfo/k3cal
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:K3CAL at mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html