Springtime Ritual #1 – Downstream Edition

Once I got the water flowing through the repaired penstock I trudged down to the turbine to check the result.  As I approached the turbine I was gratified to hear the soft whine of the mechanism, and exasperated by the sound of spraying water.  Once I got close enough to see, I noticed an absolute geyser of water spouting from the master valve that allows me to shut down the system to allow for maintenance (read: extracting fogs or crawdads from the nozzles).

So I hiked back up to the first soft joint — there are a half-dozen joints that are actually radiator hose from a bulldozer, held in place by four hose clamps (this method is designed to allow the penstock to blow itself apart without damage if there is an obstruction downstream) and disconnected it.  Yup, the master gate valve housing was split, big time.  There was no way to do anything except replace and re-plumb the business end of the system.  A hairline fracture I could possible deal with.  An eighth of an inch? Not so much.

I decided it was time to make some substantial changes to the water routing at the bottom.  as it happens I was in town, i.e. “over the mountain” on other business so I dropped into the farm supply store there to upgrade my valve system to a 2″ solid brass spigot valve rather than the low-tech, low cost, and low strength PVC sliding gate valve.

I also decided to take advantage of the opportunity of the completely disassembled plumbing to enact a longstanding goal of upgrading the system and complete the second line into the turbine housing, something I had been hesitant to do while the overall system was working well.  This upgrade 1) balances the forces on the impellor shaft by directing the water jet to strike the impeller from both sides, and 2) allows for a near-doubling of the wattage output as well.

For the connections between the new brass valve and the turbine housing I used new 1-1/8″ heater hose from the auto parts store.  The water pressure at the bottom of the system is 40-45 p.s.i so these flexible hoses should work just fine.

Finally, the new setup has me contemplating changing my strategy of mothballing the system over the winter.  Given the increased robustness of the new valve and the elasticity of the hose connections, why not just let the system run all winter long?  Water can flow well below freezing temperatures, particularly water within a pressurized construct (pipeline).  This feature is enhanced by particulates suspended in the water itself (the water coming though the pipe is very hard, essentially mineral water) so that fact alone would suppress the freezing point.  Thank you Mr. Auletta, my 9th grade Physical Science instructor, for 53 years ago relating the anecdote of the coal fields’ slurry pipelines that can keep on flowing until 15 degrees below zero Fahrenheit, or 47 degrees below freeing!  And, if I wrapped the bottom plumbing with heat tape to keep the smaller lines and the nozzles above freezing, couldn’t it keep running all winter long when our coldest temps are just barely below zero, and only for a few hours at a time?


Time to turn my attentions to the intake end of the system.