I had our tank replaced and a second field added a couple years ago. Included in the job was a bull valve on the field side of the tank output to do the same job as your valve. The valve was complete white plastic (PVC?). I exercise the valve every 30 days for peace of mind. always turns smooth.

The valves can be replaced with some shovel work if yours should fail or break. It's a good idea to alternate fields so I'd solve this problem rather than ignore it.

Thanks but not a good option and my last choice. The pipes out of the valve are 24" below surface and the surface is another 18" under a deck. Only 16" between the deck joists. Deck would need to be removed just to dig by hand. Lousy human being access so I do not want to replace unless a last resort. Looking for someone that unstuck a similar valve.
Al

You can try something like PB Blaster or Kroil. Both are sprays and excel at loosening stuck stuff. Multiple applications over time works wonders.

Make yourself a better, heavier duty tool to turn the valve. Perhaps a 3" diameter wooden dowel crosscut on the end to fit the valve?

Good suggestion. I usually like to know why something is stuck so I can be sure lube is really the way to go. I tried WD40 butr couyld not spray it well since the valve is 12" done the riseer pipe and aerosol cans do not like spraying off level. Tried some light oil but it was not feeling like the right thing so I stopped and went on vacation!
Lacking any other suggestion about why such a valve could be stuck, your idea is my next step.
Thanks.
Al

Your'e doubly cursed... metal valve and restricted access. Someone planned ahead.

WD isn't really great for freeing up seized metal parts. It was designed to displace water.

Make an extension for the PB Blaster or Kroil spray can...

Find some wire that is roughly the diameter of the spray nozzle tube and as long as you need it. Strip off the insulation and use that to extend the spray nozzle tube. Either tape the two together or use shrink wrap to connect them.

BTW, the NDS 575 valve is now ABS... click here

Not sure what I said but the valve is black plastic: both the part that turns and the housing that is exposed. Regardless, the technique for getting the penetrant to the right spot is a good one. I will give it a try.
The NDS sheet says that to 'remove inner stem' to allow all the ports to be connected. I assume (cannot see without digging) that one is to the tank, two to the leach lines and one is capped off. I I pull the stem, flow depends on gravity to take from the tank and let it take the path of least resistance to either or both lines. They do not say how to remove the stem but I clamped on to the 'handle' with some pliers and could not pull it out. Again, I am going slow and did not pull like my life depended upon getting it out! Afraid to break the plastic handle. Maybe I am making a mountain from a molehill but I do not need another PhD in the school of hard knocks. I got too many already...

Do you have the possibility of just running a new supply line from the tank to a new diversion valve where you'll have convenient access?

I finally got a call back from the valve manufacturer, NDS. The tech looked at the drawings for the valve, the guts, not just the one on the web. He said I can try any lube that does not melt the plastic and simple pull, force, etc. If it remains stuck, he said to just pull the stem (the movable part) out of the valve body since there is nothing to hold it in like a retainer clip. If I break it, he said to just get it out any way I can without breaking the housing. He would then send me a replacement stem, no charge. That is a nice offer and really lets me go forward with trying to turn it by having a way out if I break it.

Any other options make things hard and I will try to avoid any shovel work.
The lesson is that these valves are made to alternate the field lines and the homeowner should put in on his annual list of chores or he will find himself looking for answers on this forum!

Get a pair of vise grips on the valve fin(?) and use a slide hammer to pull the guts. A slide hammer is the perfect tool cause there's probably only o-rings on the valve and that's all the friction you'll need to beat.

A piece of all thread or steel rod with a hook at each end from vise grip to above grade should get you the rise you need.

You might want to get someone to put some down force on the valve body with a broom handle or something similar while you remove the guts or you risk breaking the valve body or a connection.

Don't pull the valve guts till you have the replacement parts in your hand.

Use liberal amount of plumber's silicone grease on the new parts before inserting... and time the direction of the valve correctly.

Excellant advice! It is a fin that I must grab and avoid breaking off. And the sugestion about holding down the valve housing is great since I only want to be putting force on the part I want to move.
The grease I have and will use. Have it for swimming pool o-rings and works but messy.
Will get the stem and report my success or other result.
Thanks again.
Al

I have two drain fields. A diverter is installed and the flow has been going to one drain field for a little over two years.
I want to divert to the second drain field, but I'm not sure how to tell if I have the diverter turned correctly. The installer marked the place where it is now, but did not mark a place to turn it to, to change the flow.