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Order as many mugs as you need. Make one for the office or one hundred for the big corporate party next week. No matter your quantity your mugs are custom made to fit your specific needs. The more mugs you order the more you save.
Discount
| Quantity | Discount | Savings |
|---|---|---|
| 1 | – | No discount |
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About This Design
Plumbers will enjoy this mug featuring the US Patent 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 ounces higher than the return piping. It does this by bleeding pressure into the returns after ounces was reached in the boiler. Thus, for example, if the boiler reached ounces in it, then 1 ounce would be bled into the return pipes, since at no time could the return pipes be more than 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 th century invention!
