Today has been a good day: the increasing flow available, now up to about 1.75 lps, has meant I've needed to put a bigger nozzle in. I kept the same one on the bottom and only changed the top one from ∅ 3.64 mm to ∅ 4.96 mm. An early rule I learnt was only to change one nozzle at a time, - more drastic action usually led to the header tank emptying.
Doing this lifted flow delivered to the pelton from 1.48 to 1.74 lps, and power into the grid from 343 to 421 W.
Small hands are essential and good access to the front of the turbine is helpful.
|Off with the glazing|
|The nozzle to be put in|
|Nozzle retainer spanner|
|It's a tight fit getting to the top nozzle|
|Note the cloth to stop anything dropping into the tailrace|
|There is space only in the bottom corners to remove a nozzle|
|The "whole arm in" technique to screw on the nozzle retainer|
|I use 9 different nozzles to give me flows from 1.18 to 3.43 lps|