中英文资本论经典语录中英文版
*True union design allows easy removal*All plastic construction, no rust or corrosion*Can survive corrosive environments without the need for painting or expensive epoxy coatings*Units come in PVC plastic bodies with EPDM seals*Available in ½? to 4? sizes, featuring a full-port design这个你可以直接用，应该适合于所有的球阀产品。