Hello,
I am going to replace 2 very old Stop and Waste valves in my basement. Due to some piping movement limitation I will be using soldering method. I purchased two brand new EVERBILT 1/2 in. Brass Sweat x Sweat Stop and Waste valves from Ebay. They have rubber plugs. I have few questions below.
1. Do I need remove stems from the valves before soldering to protect rubber plugs?
2. Can I just install stems back after soldering, or do I have to wrap new packing rope around the stem when I install it back?
3. I have very old (probably 7 or 10 years old) Oatey N0. 95 Solder Tinning Flux Paste left from my previous home project . Can I still use that paste or do I need to buy a new paste?
4. Some youtube videos recommend using low melt solder for soldering 1/2" copper pipes? Does it really necessary? Where can I get low melt solder?

Thank you very much in advance for your answers and suggestions,

 

Rubber plugs ??
Do you mean the drain caps ?
Yes... you should unscrew them.
No need to take valve apart.... just make sure it's open.

As long as that old flux is clean.... it should be fine.
Standard plumbing solder is fine. It's pretty much low heat.

You want to make sure the pipe is CLEAN. Emery cloth works well. Scotchbrite pads... green and brown are good too. Clean the pipe and then clean it again. Make sure to clean the inside of the valves. Any dirt in/on the pipe or in the flux will cause problems.

 

S-

We are not talking about a lot of money here. Why not use ball valves? Those are much better. I think there is pretty much widespread agreement about that. I think there are far fewer problems with ball valves.

https://www.homedepot.com/p/Everbilt...53EB/205822401

 

You never want to replace anything with gate valves, always use ball valves.

Get new flux and solder, contamination is the culprit for leaks, along with not cleaning the soldered surfaces. For the few dollars it cost you want to do it right the first time.

I'm convinced this is one of the main issues people have with sweating joints, it's an easy process but people make a simple mistake and then the process becomes black magic!

 

Hi,
I am not a plumber. Can you please give me the reason why "You never want to replace anything with gate valves, always use ball valves" and what is the problem with gate valves?
Also, why ball valves have different handle colors: blue, red, yellow?

 

For the reason your changing them now, thy are just a cheap, less efficient valve.

 

Here is an excerpt from the following article:

(for some reason I'm not seeing any formatting capability for this post, but the quote from the article is between the asterisks)

https://www.processindustryforum.com...-vs-gate-valve

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"Are ball valves better than gate valves?

To settle the ball valve vs gate valve debate, we opened up the discussion to leading Scottish industrial valve distributors, BM Engineering Supplies, who stock both valves types. They stated that the benefit of a ball valve vs a gate valve is that they seal much tighter, therefore making them better at avoiding leakage than gate valves. This is due to their 100% shut off characteristics. In addition, they are also easier to use than gate valves, offering both lower rates of failure and greater longevity.

The durability of ball valves makes them an ideal choice for shutoff applications. They perform consistently well after many cycles, as well as boasting reliability and the ability to close securely even after long periods without use. For these reasons, they are often preferred over gate and globe valves."
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You hear about a lot of cases where when people go to use a gate valve that hasn’t been opened/closed for a long time, they get an unpleasant surprise- and you also hear about a lot of leaks. You may close the valve and not get a complete shutoff.

You don’t hear that about ball valves. You can even see many cases of the above on this forum.

 

Thanks a lot for all your explanations and suggestions.

 

One more question. Do I need to keep the ball valve open when I solder it or do I need to keep it closed?

 

Hello,
I have a simple for each plumber question. I will replace my very old leaking Stop and Waste gate valve with a 1/2 in. Forged Brass Sweat x Sweat Stop and Waste Ball Valve. Do I need to solder the ball valve in open position or in closed position?

https://www.homedepot.com/p/Everbilt...53EB/205822401

Thanks a lot in advance for your answers.

 

Have it in the open position. The heat will get to the seals either way. But, with the valve open the air inside the pipe, heated by the torch will expand, and the open valve lets the air escape without bubbling through your solder joint.

 

Thanks a lot. I was more concerned about solder flowing into the opening and blocking the valve.