On 03/06/2012 10:15 AM, Oren wrote:

[snip]

Called a _Swing Pipe Assembly_

• Primary Application: Residential Installation

• Allows to minimize overall system depth underground

• Swing motion allows for easy and accurate depth setting of the
sprinkler head

• Allows easy parallel connection of sprinkler heads to main
irrigation line.

http://www.rainbird.com/homeowner/products/accessories/SwingPipeAssembly.htm

They also allow for some stress relief in case you step on the
sprinkler head. You can even buy them in metal, that flexes.

I have one sprinkler head that won't come up any more (although it still
sprays) because of a tree root that grew over the top. That _Swing Pipe
Assembly_ would have made it easier to fix.

--
Mark Lloyd
http://notstupid.us

"Question with boldness even the existence of a god; because, if there
be one, he must more approve of the homage of reason than that of
blindfolded fear" -- Thomas Jefferson, 1787