10psi differential on pressure switch?

Discussion in 'Pumps and Tanks Well Forum & Blog. Water is life.' started by JasonA, Jun 23, 2020.

  1. JasonA

    JasonA New Member

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    victoria, BC, Canada
    I am a farmer. For irrigation I have a pond, and a F&W 2 hp 230v pump (SP20P1) and an 80 gall pressure tank. Although it is rated for more, the pump max pressure is 40psi. Most mechanical pressure switches appear to have a 20psi differential that you can only raise but not reduce, so on a 40 cut off this means the cut in pressure is 20psi. I'm finding that low pressure is too low to run my sprinklers properly - they want at least 30psi.

    Is there a pressure switch available - electronic or mechanical - where I can set the differential to 10psi, and run the pump between 30-40psi?

    Thanks, Jason
     
  2. Reach4

    Reach4 Well-Known Member

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  4. valveman

    valveman Cary Austin Staff Member

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    It should only go down to 20 until the tank is empty and the pump starts. When the pump comes on it should stay on (not cycle) as long as the sprinklers are running. If the pump is cycling on/off between 20 and 40 while the sprinklers are running, then cycling is your problem, not the bandwidth of the pressure switch.

     
  5. ballvalve

    ballvalve General Engineering Contractor

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    https://www.grainger.com/product/SQUARE-D-Water-Pump-Pressure-Switch-2PXY6 You have about 50 to choose from and a vast range of pressure differentials
     
  6. JasonA

    JasonA New Member

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    Thanks ballvalve. I spent a lot of time on the phone with Grainger before posting here. As you say there are many pressure switches that cover a wide range of pressures. What there do not seem to be though is the ability to reduce the differential - the difference between the cut off pressure and the cut in pressure. Most mechanical pressure switches have a 20 psi differential, and some allow the cut off side to be changed but mostly to increase it, not to decrease it by much. The lowest differential I found on a mechanical pressure switch is 15 psi and I have one on order to see how it goes.

    Reach4 posted earlier about an electronic switch, the EPS15/99. I replied to his post but I can't see it so perhaps I did something wrong. I've love to get my hands on one of those because it seems you can set the cut off and cut in switches to whatever you want. But I'm in Canada and although the switch sells in the States for $30, because UPS is involved in the shipping, the EPS15/99 becomes $140 when you add on their exorbitant freight and handling charges. I noticed too a 2013 post from valveman saying he had a 15% failure rate with those.

    Valveman also pointed me to the Cycle Stop Valves. They look great but the freight might be prohibitive - I will have to follow with him.
     
  7. Ryan Symons

    Ryan Symons Dihydrogen monoxide specialist

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    Adjusting the nut on the short stud raises/lowers the cutoff pressure only. With this you can adjust the differential to whatever you want it to be. Then adjust the tall one to move that new pressure range up or down.
     

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  8. JasonA

    JasonA New Member

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    I wish it was that easy :) The adjustment for the cutoff pressure is mostly to increase the cutoff pressure. If you try to loosen it at best you can only lower the cutoff pressure by 5psi. I believe the electronic pressure switches allow you to have any differential you want, but not the mechanical ones.
     
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  9. Reach4

    Reach4 Well-Known Member

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    I expect you can get it sent via the post office for less money. There is still a customs fee, but I have read that Canada Post only charges C$10.
     
  10. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

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    The thing that kills pumps is frequent on/off cycles. They work much better, longer, when they run for some minimum time in between. Changing the differential would mean in constant use that the pump will cycle on/off frequently and not run as long...not a good solution!
     
  11. valveman

    valveman Cary Austin Staff Member

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    I am sorry for your problem. We are just about to stop selling anywhere except the US. Shipping out of the US, other countries put on these customs and handling fees that make our $30 switch cost $140 and take forever to get there. It makes it really hard for US products to compete in any other country. But when the US tries to impose fees or tariffs to other countries, they throw a fit. :mad:
     
  12. ballvalve

    ballvalve General Engineering Contractor

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    The Chinese are able to send parcels here via the USPS for next to nothing under some old program. I bought a usb cable and it came from China for 26 cents. 10 brass valve caps, 98 cents and shipping included. I HP submersible pumps with control box and wires $129 delivered. Makes me sick.
     
  13. ballvalve

    ballvalve General Engineering Contractor

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    Symons is right. You should study that page and not call Graingers where you get bad information. All the good information is in the book.
     
  14. Chucky_ott

    Chucky_ott Member

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    When you import into Canada, you may need to pay 5 things: the item, shipping fee, Canadian sales taxes, duty fees, brokerage fees.

    It is that last one that will usually be high for low cost items. Fortunately, USPS does not charge brokerage fees when shipping to Canada (at least they didn't last time I purchased something from the US). And duty fees are usually reasonable, if applicable.

    UPS, Perolator, FedEx all charge high brokerage fees, frequently just to tell you that there are no duty fees to pay.

    If the shipper can use USPS, that's what you should use.
     
    Last edited: Jun 29, 2020
  15. valveman

    valveman Cary Austin Staff Member

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    Was using USPS, now they have changed things up and take forever and charge too much as well. I blame the US government for this mess. Every other country in the world makes money off the US with products coming and going. They sell cheap products to the US without any added fees. But when we try to sell outside the US, they let other countries add a ton of fees to our stuff.

    I can't sell anything in Mexico if it has even one screw made in China. Most manufacturers are forced to build a manufacturing facility overseas, so they don't have to ship from the US and get priced out of business. 25% tariff isn't enough. The US needs to charge the same fees for incoming products as each country charges us to ship to them. The trade war has been so lopsided for so long it is a wonder any US manufacturers are still in business. Between excessive regulations, taxes, insurance, lack of people willing to work because they get paid too much for unemployment, and the fees we have to pay to do business overseas, US manufactures are working with both hands tied behind our backs.
     
  16. ballvalve

    ballvalve General Engineering Contractor

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    If your product has some Chinese content, you can just follow the Chinese ethics and lie and falsify records. So much comes from Vietnam in furniture and honey and fish because they are toxic and dumped from China where the export is prohibited. So Vietnam just stamps a new "Made In" tag on and the Chinese bypass our reg's. We are the worlds dupes, and about the best thing to come from the president is his taking on the Chinese for their dumping crap on us. Also kicking out NAFTA. As for our workforce, having had a large manufacturing company, I am troubled by the lack of a work ethic. And skills. And dedication to purpose. But they do seem to be very productive with spray paint and pulling statues over.
     
  17. valveman

    valveman Cary Austin Staff Member

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    Agreed! We are the worlds dupes. Like I said every country in the world makes money off the US with products no matter if they are coming or going. We just keep paying for products that were produced overseas using our stolen technology, or technology we just gave away. Then we let all other countries put tariffs and fees on anything purchased and shipped out of the US. The cost of labor, insurance, and excessive regulations already makes products produced in the US many times more expensive than products from other countries. I too am very troubled by the lack of work ethic and skills. Most applicants couldn't change the oil in a lawnmower if they had to, as they don't even know which end of a screwdriver to use. There is absolutely zero dedication to purpose or want to work anymore. They can make more money on unemployment and will just walk off the job for any reason, especially if you really want them to show up and actually do something. Schools need to bring back shop, mechanics, ag, and make those classes mandatory for everyone. Those kids could even do a better job of tearing down statues if they had taken a shop class. LOL!
     
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  18. ballvalve

    ballvalve General Engineering Contractor

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    Yes, the shop classes need to be in all schools - manual arts sounds better to todays mothers. And I will be happy to sell back all the machinery I acquired at auctions of school machinery when they closed down... Most of those bought at 2 cents on the dollar.

    As for American Ingenuity we have Tesla and Musk.... but wait. He is a South African immigrant. Ok, then how about Google - started by Sergey Brin, and worth 64 billion take or give a few billions! OOps, he is a Russian immigrant. So George Soros, 20 billion net worth. Guess again, Hungarian born. Another one! Well, we still have Microsoft, Walmart, Ford and Apple that are homegrown. And then Warren Buffet, that delivered newspapers to buy his first stock at age 11. Now worth 87 billion. What in hell do you do with that?

    But that old adage, "adversity is the mother of invention" stands true. Even though America has lost so much of its industry we still remain about the same as China in production, though due to inflated prices of weapon systems. We do remain an incubator for innovation and success that no country has yet to match. Whether or not we have become fat and lazy to the point of terminal deterioration is yet to be seen. Still some good corn fed kids coming out of the Midwest prairies.
     
  19. valveman

    valveman Cary Austin Staff Member

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    Lol! Right on the money! Not too many farm kids left to hire anymore. My choices for someone who knows how to work a screwdriver are either someone raised on a farm, or someone over 60. But in spite of the labor problem and all the other hurdles we have to jump, American industry is still thriving. Just think what we could do if our government would quit tying our hands behind our backs?
     
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