R&D History--8 Jan 2020 Test

  Next we created "internal vent" fuel caps by drilling a threaded hole down to within ¼” of the bottom of the cap. A small offset hole was drilled the rest of the way through as a vent path.

  A hollow sphere "float switch" was inserted into the hole, then a hollow set screw with an O-ring was threaded into the  hole.

  The sphere fell when no fuel was present, allowing air to flow up and out through the set screw to vent the tank.

  The sphere floated up to the O-ring seal to prevent overflow.  

   This video documents tests of a brass external vent affixed to our prototype fuel caps.  

   Although we did achieve some successes (one of the generators ran over 20 consecutive hours under heavy load) the results were inconsistent and certainly not marketable.  

   However these tests did help lead us to the elegantly simple and robust final design that we market today.

  Still experimenting to see if placing a combination vent/overflow shutoff valve on the fuel cap was feasible—this video documents our tests of two external valves. 

  One valve's “cracking pressure” was 1 psi, (when the vacuum inside the internal tank built up to 1 psi pressure, the valve would open and allow the tank to vent). The other valve's cracking pressure was only 1/3 of a psi.

  Although both valves did permit some external fuel to be consumed, neither valve produced consistent results.

Internal float test

   This test evaluated the possibility of using a “float” inside the fuel cap to press a sealing disk up against the bottom of the cap to affect a seal and prevent overflow. 

   The weight of the float did create a vent path, but it did not affect a fuel-proof seal sufficient to prevent overflow.

Open Vent Line Test # 1

   Still experimenting with ideas for incorporating a vent into the generator’s fuel cap, this experiment tested the hypotheses of what would happen with a completely open vent line running out of the fuel cap.

   The generator still didn’t pull fuel from the external tank.

   This video documents our second science experiment with an open vent line running up from the fuel cap to a level above the external fuel tank. 

   The generator burned all of the internal fuel, but very little of the external fuel.

MERGS Squeeze Bulb Bypass Test 

                11 - 12 Oct 2020 

   We finally realized that the vent line was not the problem. The problem was the one-way check valve in the squeeze bulb. 

   Sometimes the vacuum pressure in the internal tank would be sufficient to crack the one-way valve open and permit fuel to flow down into the tank.

   Other times the carburetor would starve before the one-way check valve would crack open.

Capped Vent Test 13 - 14 Oct 2020 

The purpose of this test was to see if we could eliminate the vent line from the cap, and just use the vent in the external tank. The test was successful, although the Rube Goldberg squeeze bulb work around loop gave us some consistency issues in this test.

  M E R G S Gravity Feed Test 20 - 21 Oct 2020 

This video documents our first pure gravity feed test with no squeeze bulbs to work around. The marine-grade non-spray fuel connectors worked perfectly, and the test was a complete success.

  This video does a good job of introducing the marine-grade non-spray fuel connectors that work so well with the MERGS system. There is some discussion about manufacturing our own tanks, but we subsequently became enamored with the 20 liter (5.3 gallon) military-grade fuel tanks produced by Scepter, so there was no need to manufacture our own custom made tanks.

   This highly successful test of our new factory production fuel caps ran two Powerhorse 2000 generators for over 25 hours at just under 50% max continuous load.  Both generators still had 1/2 their external fuel when test was completed.  

   New brass & stainless steel vent system was added to external tanks later.