[A/S] Faulty valves?

["Tim Shephard" <timshephard@xxxxxxxxxxxxx>]

I replumbed my entire trailer and used ball valves at the drain lines coping
the original copper drains.

When the valves are closed and I presurize the system with the water pump or
external hose the drains dribble a little water through them.  When the
water pump is used it runs a little every few minutes because of these
leaks.

I replaced two of them and the new ones do the same thing.

Any ideas why this is happening?  Do ball valves leak a little by design?

-Tim
tim@telecom-pros.com
http://www.telecom-pros.com/tim/tim