Nos. 28676, 28810. May 20, 1971. William A. Brown, Houston, Tex., Guy Farmer, Washington, D.C., Richard C. Keenan, New Orleans, La., Patterson, Belknap, Farmer, Shibley Wells, Washington, D.C., Kullman, Lang, Keenan, Inman Bee, New Orleans, La., Powell, Brown Maverick, Houston Tex., for Southwestern Pipe, Inc. Marcel Mallet-Prevost, Asst. Gen. Counsel, N.L.R.B., Nancy M. Sherman, Washington D.C., Clifford Potter, Director, N.L.R.B., Region 23, Houston, Tex., Arnold Ordman, Gen. Counsel, Dominick