SpudFiles

i see all u guys talking about how sdr-21 is weak. but looking at this charthttp://www.harvel.com/pipepvc-sdr-dim.asp of sdr-21 and then this charthttp://www.harvel.com/pipepvc-sch40-80-dim.asp i see that sdr-21 at 1.5inch has a wall thickness of .090 and a pressure rating of 200psi and then sch40 has a wall thickness of .145 and pressure of 330psi

so is sdr-21 really that weak.

and if i were to go about sleaving in is that just putting the sdr-21 pipe inside of the sch80 2 inch pipe.

i am looking for about a 4 foot length for this barrel

thanks alot,
Joe

It's recomended, but not required in most situations. In normal pressure applications, like a chamber for instance, you could certainly use sdr 21. However, when you start to apply different types of loads, like "crush" loads (stick pipe in vice type) it becomes a different story.

...For non-coaxial barrels that are short enough that bending isn't a problem, you'll be fine using it unsleaved. I'd sleave it for a co-axial anyway... just thinking about what a wall that thin would do to a peice of rubber is giving me the chills.

BLB is right, the reason is also like he said that the reason why it is sleeved the pipe not because pressure, but for other forces acting on the pipe. (ECHO, Echo, echo!). The sun is evil when it comes to thin plastic. All of my unsleeved barrels all now have a slight bend to them (works good if you point it right because it acts as a pop up device) Sleeving is defently recommend even though you can have just the SDR21 by itself.