Symmons Washer Valve replacement

My old Symmons valve does not shut off my water. I bought a new one at Home Depot and the plumbing guy said I could install this without soldering. The instructions say to 'sweat' the valve on the incoming water pipe...what does that mean? Doesn't it mean 'solder'? If not, I don't see how they stay together....I hope I'm just missing the obvious...please help!

OK, I'm back after reading some posts on this site. Looks like sweating means soldering. If so, how do I take the existing valve connector off the incoming pipe? Will it slip off when I heat it up or does it need to be cut off?

You're right, sweating=soldering, but sounds like you got the wrong valve. If the old valve screws on to the pipe, then you just need a screw-on replacement valve. What you want is a ball valve that takes just 1/4 turn to go full off to full on and are full flow valves. It will look very much like the one you got, but will have threads. However, if you are using screw together fittings, you must have a union in the line.