Profile: Dallas Specialty & Mfg. Co. provides products and service to the wholesale plumbing, irrigation, waterworks, tile and home center industries. Our flexible PVC pipe couplings are used for connecting sewer & drain and DWV piping systems to a variety of piping systems. We offer dal-sleeve, which is used for corrosion & abrasion protection of potable water lines and tubing in underground installations and penetration of concrete floors & footings.