Allowances may be made for the expansion and contraction in piping by the use of expansion
Allowances may be made for the expansion and contraction in piping by the use of expansion joints or ().
A.Unions
B.Retractable flanges
C.Union bulkhead fittings
D.Bends or loops in the line
请帮忙给出正确答案和分析,谢谢!