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ST9302-CS 990712The City With A Beautiful Future P.O. BOX 478 COPPELL, TEXAS 75019 Robert Weber, Project Engineer Ed Bell Construction 10605 Harry Hines Blvd. P.O. Box 540787 Dallas, TX 75354-0787 Re: Sandy Lake Road Project # ST 93-02 [~ ,~.;.~ Comb. Air Release Valve (30" & 16") J ~2 '~ Dear Mr. Weber: DATE 7 The purpose of this letter is to clarify pay item #104, Air Release Valves. The plans specify a "type 2" air valve, as shown in COG's Standard Specifications, Standard Drawing No. 4100A. One air valve has been installed at Sta. 11 +50 on the 16" water main, utilizing the City of Coppell's Standard Detail.~. This design would be acceptable up to two-inch (2') pipe size. However, using three- inch (3") copper pipe with the City of Coppell detail presents maintenance problems. Three inch (3") copper pipe requires sweated joints which will be under new concrete paving and has a high potential for leaks. The one air valve installed has already required repairs for a leak at a sweated joint. On all air release valves please use the "type 2' as shown in COG's Standard Specifications, Standard Drawing No. 4100A. 'No price increase or need of change order would be needed since this request conforms to the construction plans. Also, please submit a price for removal and replacement of the existing air valve with a "type 2" air valve at Sta. 11+50. If you have any questions or need more information please feel free to contact me. Sincerely, Kenneth M. Griffin, P.E. Diro~_...or of Engineering/Public Works Lee ~ Kimlcy Horn Sun p~m'?~, ~r COPPELL, TEXAS 75019 Robert Weber, Project Engineer Ed Bell Construction 10605 Harry Hines Blvd. P.O. Box 540787 Dallas, TX 75354-0787 P.O. Box 478 Coppell, Texas 75019 972-462-0022 July ~12, 1999 Sandy Lake Road Project # ST 93-02 Comb. Air Release Valve (30" & 16") Dear Mr. Weber: The purpose of this letter is to clarify pay item #104, Air Release Valves. The plans specify a "type 2" air valve, as shown in COG's Standard Specifications, Standard Drawing No. 4100A. One air valve has been installed at Sta. 11+50 on the 16" water main, utili~.ing the City of Coppell's Standard Details. This design would be acceptable up to two-inch (2") pipe size. However, using three- inch (3") copper pipe with the City of Coppell detail presents maintenance problems. Three inch (3") copper pipe requires sweated joints which will be under new concrete paving and has a high potential for leaks. The one air valve installed has already required repairs for a leak at a sweated joint. On all air release valves please use the "type 2" as shown in COG's Standard Specifications, Standard Drawing No. 4100A. No price increase or need of change order would be needed since this request conforms to the construction plans. Also, please submit a price for removal and replacement of the existing air valve with a "type 2" air valve at Sra. 11 +50. If you have any questions or need more information please feel free to contact me. Sincerely, Kenneth M. Griffm, P.E. Director of Engineering/Public Works Lee Allisoll, Kimley Horn Sm Ph~!l'.ms, Impm~r