【单选题】
低压加热器采用的堵头要求为()。
A、长约50mm,锥度为1:20,大端比管孔大0.025~0.05mm
B、长约40mm,锥度为1:25,大端比管孔大0.025~0.05mm
C、长约40mm,锥度为1:20,大端比管孔大0.025~0.05mm
D、长约50mm,锥度为1:25,大端比管孔大0.025~0.05mm
A、长约50mm,锥度为1:20,大端比管孔大0.025~0.05mm
B、长约40mm,锥度为1:25,大端比管孔大0.025~0.05mm
C、长约40mm,锥度为1:20,大端比管孔大0.025~0.05mm
D、长约50mm,锥度为1:25,大端比管孔大0.025~0.05mm