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Sale Price $18.11.  
Original Price $21.30 Comp. value
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Plumbers Do It With Pressure Hoffman Differential Coffee Mug

Qty:
Classic Mug
+$1.15
+$2.30
+$5.80
+$6.95
+$9.25
+$11.55

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Style: Classic Mug

Give a made-to-order mug from Zazzle to someone special, or treat yourself to a design that brings you joy or makes you laugh. Create your own photo mug, shop our collection of the funniest joke mugs, personalize your mug with a monogram, or express yourself with one of our 10 million designs.

  • Available in 11-ounce or 15-ounce
  • Dimensions:
    • 11-ounce: 3.2” D x 3.8” H
    • 15-ounce: 3.4” D x 4.5” H
  • Microwave and dishwasher safe
  • Use caution when removing the mug from the microwave. Use a pot holder or glove as necessary if it is too hot to the touch. Do not microwave an empty mug
  • Strong, ceramic construction
  • Meets FDA requirements for food and beverage safety
  • Printed on demand in Reno, NV
  • Do not overfill and be careful with hot liquids that may scald
  • Keep out of reach of children when filled with hot liquid

About This Design

Plumbers Do It With Pressure Hoffman Differential Coffee Mug

Plumbers Do It With Pressure Hoffman Differential Coffee Mug

Plumbers will enjoy this mug featuring the US Patent 1777333 by William K Simpson for The Hoffman Differential Loop along with the truism saying "Plumbers Do It With Pressure." The Hoffman Differential Loop, a device with no moving parts, keeps water in the boiler by making sure that under no circumstance could pressure in the boiler exceed 10 ounces higher than the return piping. It does this by bleeding pressure into the returns after 10 ounces was reached in the boiler. Thus, for example, if the boiler reached 11 ounces in it, then 1 ounce would be bled into the return pipes, since at no time could the return pipes be more than 10 ounces different than the boiler. What this means is that water would always be able to return to the boiler and steam would always flow since there was a differential pressure between the supply and return pipes. This device maintains an unvarying water line in the boiler independent of boiler pressure, which means that water in the boiler is never lowered to a point where the heat from the fire can exert a destructive influence on the boiler. Celebrate technology that is still applicable today in the home heating systems of old houses with this mug featuring a 20th century invention!

Customer Reviews

4.8 out of 5 stars rating21.8K Total Reviews
19280 total 5-star reviews1841 total 4-star reviews333 total 3-star reviews143 total 2-star reviews227 total 1-star reviews
21,824 Reviews
Reviews for similar products
5 out of 5 stars rating
By R.May 16, 2020Verified Purchase
Classic Mug, 11 oz
Zazzle Reviewer Program
Got a personalized coffee mug for my husband as a birthday gift from our kids. He lovessss it!! Turned out really nice! The pictures were really clear!! Great product!! The pictures were really clear!!! They turned out great!!
5 out of 5 stars rating
By Maureen Z.May 8, 2022Verified Purchase
Classic Mug, 11 oz
Zazzle Reviewer Program
It is a lovely mug. The actual mug is shiny and smooth. Very nice quality. It was everything I expected. Zazzle has so many nice mid century modern designs to choose from. All so pretty! The design was very clear and looked expensive.
5 out of 5 stars rating
By Chayt C.October 5, 2020Verified Purchase
Two-Tone Mug, 15 oz
Zazzle Reviewer Program
The mug feels really nice; it's kind of heavy, which I like. It was made, shipped and arrived within eight days of when I completed my order. Two corners of the box were smushed, but that's most likely the fault of the postal service or my little brother, not Zazzle, and the mug itself was perfectly intact. It was a bit dirty when I opened the box but that was expected and easy to clean off. I love it! The photo I added was perfect and everything lined up just as I expected; the only issue I found is that the heart on it turned out closer to off-white, when I was expecting more of a light grey, but other than that it's wonderful.

Tags

Mugs
hoffman differential loopplumbersdo it with pressureplumbing technologyus patent 1777333older home steam heating systemplumbing inventor geek humorhoffman equalizing loopboiler pressureinventor invention
All Products
hoffman differential loopplumbersdo it with pressureplumbing technologyus patent 1777333older home steam heating systemplumbing inventor geek humorhoffman equalizing loopboiler pressureinventor invention

Other Info

Product ID: 168342932306567188
Created on: 8/11/2022, 2:02 AM
Rating: G