Spiro Royal Mistral o-rings...
Posted: Sun Jan 28, 2018 9:21 pm
I'm in the final stages of rebuilding my Royal Mistral, now all pulled down, given a light pickle in 50:50 white vinegar and water then ultrasonic cleaning in Simple Green crystal. Came up like new 
I finally found an English translation of the original French Spiro service manual and it lists a R6 o-ring for the removable volcano orifice... and no others.
R6 is a relatively obscure French Metric size ID 7.2mm x 1.9mm 90 Duro
So I was a bit surprised when disassembling the main block to discover another small quite hidden o-ring used to seal the pin!
The US Divers Mistral uses a -006 seal in the same place (ID 2.9mm x 1.78mm) but as all other aspects of the Royal Mistral are in Metric it is subtly different... carefully measuring the old o-ring I determined it is a R1 ID 2.6mm x 1.9mm.
ERIKS Industrial Services UK has the French R series in stock, as do Marylands Metrics in the US... has anyone else struck this issue?
https://mdmetric.com/or/frenchgb.htm
I finally found an English translation of the original French Spiro service manual and it lists a R6 o-ring for the removable volcano orifice... and no others.
R6 is a relatively obscure French Metric size ID 7.2mm x 1.9mm 90 Duro
So I was a bit surprised when disassembling the main block to discover another small quite hidden o-ring used to seal the pin!
The US Divers Mistral uses a -006 seal in the same place (ID 2.9mm x 1.78mm) but as all other aspects of the Royal Mistral are in Metric it is subtly different... carefully measuring the old o-ring I determined it is a R1 ID 2.6mm x 1.9mm.
ERIKS Industrial Services UK has the French R series in stock, as do Marylands Metrics in the US... has anyone else struck this issue?
https://mdmetric.com/or/frenchgb.htm