Document JOgmX0ymzZpeadYweX8nrxLe

S*n Prancisco Office Power Generation Service Div. Mr. R. L. Bergquist (,roi 0m East Pittsburgh, CC28 236-2892 / / Ae .April 11, Suuca CttX-o*-attle - Roe* % Pwtrtam Generators n 1# 2, 3839*67, A 1353*5(5 O: is cc: 2:;s - East Pgh. Div. - LM Sales - Mr. S. J. Smith Vb* cc: 5**3 - East Pgh. Div. - Hydro Engineering - Mr. E. C. Whitney __- [)z: i cc: 2G - East Pgh. Div. - Industrial Hygiene - Mr. H. W. Speciber^^' cc: Seattle - Power Systems Sales - Mr. A. W. Kessler * ' jj^. cc: San Francisco Pwr. Generation Serv. Div. - Mr. M. J. Locklear r-- I have reviewed your letter dated March 29, 1973 with Mr. E. C. Whitney aad Mr. P. L. Kaspbaus, and they have furnished me with the followingr 1 nfe. "This is the first time that ve have heard that there is a noticeable mount of dusting frca the v~rake shoes on these units. We can not eliminate the duetlng a*! the people at the parerhouse do not have to go in very often, in fact they should not go in at all. They can vacuum the place and only go in 20 minutes after the unit has etmm to rest so that the dust will have settled. Ve also should adrlee the Customer that he should not apply the brakes until the unit coasts down to about 20} speed which would reduce the dust considerably. 'l Also, if a pressure reducing valve is installed in the air feed to the brakes i so that he does not apply more than 90 to 90 PSI, it will redact the wear of the shoes and extend the stopping time unless the gate leakage torque is greater than 1}f which is very unlikely. We are inclined to feel the labor is "on edge" to even bring this up aa it is considered quite minor for a short tine unless the man works aad stirs up the dust while working. Perhaps they do need to vacuua the area". 0E PC Liac a. 1. Smallwood, tonager Bdqtrs. Generator Service <s* M) r