Threaded PVC pipe used in deep wells for level transducer protection?

[ibewsparky55]

Hello all,

I'm looking for a particular threaded PVC pipe/tubing that I've seem used in deep wells for the protection of level transducers installed down the well. The pipe is in 10' sections, fairly thin-walled (I believe thinner than schedule 40) and has very unique steep-pitched male/female threads (not NPT) on each end to screw the sections together. This pipe/tubing is then secured to the side of the discharge column piping as it's placed into the well. Can anyone point me in the right direction to find this particular type of pipe/tubing? Thanks in advance for your help with this.

Monty

 

[Boycedrilling]

Yes it’s flush threaded pvc pipe. Male x female astm acme style threads. It also has an o-ring seal. I use monoflex brand. I buy it from Preferred Pump in Pasco, WA. For a transducer you will want 1” or 1 1/4”. I have 500 ft strings of both for my test pumps. I attach it to the drop pipe with stainless steel banding material

It is available in schedule 40 and 80. I use sch 40. It threads together by hand. It’s the same stuff we use for 2” monitoring wells.

You can get it from Preferred Pump, 2M, Western Hydro, or Mitchell, Lewis & Staver. They will probably have to order it.

 

[Sponsor]

 

[Valveman]

If you are looking to control the pump by the water level in the well then ok. De-watering wells and such can be held at a certain level. And a transducer down the hole when testing a well like Boyce works really well. But if you are just trying to protect your pump from running dry, there are much simpler and more reliable ways of doing that. VFD's normally have a dry run feature and regular pumps can use a Cycle Sensor to shut the pump off when the amperage is so low it could only be pumping air.

 

[ibewsparky55]

Yes it’s flush threaded pvc pipe. Male x female astm acme style threads. It also has an o-ring seal. I use monoflex brand. I buy it from Preferred Pump in Pasco, WA. For a transducer you will want 1” or 1 1/4”. I have 500 ft strings of both for my test pumps. I attach it to the drop pipe with stainless steel banding material

It is available in schedule 40 and 80. I use sch 40. It threads together by hand. It’s the same stuff we use for 2” monitoring wells.

You can get it from Preferred Pump, 2M, Western Hydro, or Mitchell, Lewis & Staver. They will probably have to order it.

Boycedrilling,

Thanks for your reply and the information. That's exactly the pipe I was tring to find. I noticed that one brand is available in a schedule that is slightly thinner wall than Schedule 40 (Monoflex SDR 21 / SDR 26). I don't really need Schedule 40 but maybe it's more readiily available than the others. Anyway, thanks again for your help with this!

Monty

 

[ibewsparky55]

If you are looking to control the pump by the water level in the well then ok. De-watering wells and such can be held at a certain level. And a transducer down the hole when testing a well like Boyce works really well. But if you are just trying to protect your pump from running dry, there are much simpler and more reliable ways of doing that. VFD's normally have a dry run feature and regular pumps can use a Cycle Sensor to shut the pump off when the amperage is so low it could only be pumping air.

Hi Cary,

In this situation the well level would be the controlling input signal to an HMI PLC that would then interface an output to a VFD for variable speed regulation. This is for a 480, 3-phase, 150HP deep well submersible. The pump is sitting at around 1,000' and the static well level can be as high as 80' below ground level so running this pump up to full speed at this high static level could result in some very excessive initial flows and pressures. The PLC interface will look at the well level and then ramp the pump up to a setpoint maximum speed based on the level of the well to prevent excessive flow and pressure. As the well level is drawn down the PLC will then step the pump speed up progressively trying to find that happy medium where the pump speed maintains acceptable flow and pressure rates while well level remains somewhat constant. We'll see how it works out.

Monty

 

[Valveman]

Well that is a good application for a VFD and a level transducer. That is what Boyce is doing with those to test wells. I hope it doesn't give you technical problems and last a long time. If it does use the info for a guide to size the next pump correctly and install at the right depth (test the well) and you can do away with the VFD.

 

[Boycedrilling]

When I test pump a well, I’m running a water level probe inside the pvc sounding tube to take the water level measurements. I’ve pulled the probe off of too many water level testers over the years. Many times we will also run an electronic transducer to monitor the water level, in addition to taking manual water level readings. Then I run two strings of pvc sounding tubes.

Most municipal pump installations around here, that use a VFD to control the pump output include a down hole transducer to keep from overpumping the well.

 

[Valveman]

There are a couple million pumps in cotton fields around here. They use a regular gate valve for a choke and a sight glass. Bubbles in the sight glass mean they need to choke the pump a little more.

 

[VAWellDriller]

I do the same as Boyce testing wells, but I use thin wall 1" PVC....its called 200PSI irrigation pipe around here. We put 1 or 2 tubes in beside test pump, take hand measurements and use Solinst level transducers to record water level. The pipe is really cheap, and we glue it together and put it in by hand a stick at a time; wait about 20-30 seconds for glue to set. We have deep wells here, but deepest I ever need to set a pump and tube is 300-400. We hang it with riser clamp, and cut it through it away when we're done or give it to irrigation guys. It comes with a long VERY thin bell end. SCH 40 couplings make too much snag to reuse the pipe. Sometimes we use on permanent install to and tape it to drop pipe with 2" PVC pump tape.

 

[Valveman]

Down hole pressure transducer were not even around a few year ago when I was still testing wells. We used a 1/4" poly line with a 1/4" tee up top, which included a pressure gauge and a Schrader valve. Using a small air compressor we would pump up the 1/4" line. For every pound of pressure on the gauge there was 2.31' of water above the pump. You could see the water level drop as the well was being tested this way. If the water level was dropping too much, we would adjust a gate valve accordingly until the level stabilized. Then we would know how much water the well could make and from what depth. It was simple and very reliable. The whole thing cost less than 50 bucks, and we normally just left it in the well so the well owner could check his water level anytime he wanted.

 

[Boycedrilling]

A lot of engineers want accuracy to 1/10 foot or less when we test pump. They really want accuracy to 1/100th foot.

 

[Valveman]

Lol! I don't think the surface of the water when testing a well is calm enough to even be that accurate. The more information you give them, the more dangerous they are. I am always glad when they say they are going to lunch or something and will be back in a few hours. It is amazing how many problems get solved, how much gets done, and how things are running so much smoother by the time they get back.