The utility model provides an integral petroleum production tree, which is characterized in that a pipecross and mutually connected main bars are a hollow and cuboid integral forging piece;
本实用新型提供一种整体式采油气树，其特征是四通和相互连接的主杆为一个空心长方体的整体锻压件；
2
Regulating regimes of metered heating system are analyzed by means of computer simulation. This paper gives the control mode of consumer heat inlet that applies to one-pipecross-over heating system.
通过计算机模拟分析了计量供热系统的调节工况，给出了适用于单管跨越式供热系统的热力入口控制方式。
3
The stress distribution of a curved pipe with an initial elliptic cross section under internal pressure was studied by using electric resistance strain method.