The comparison of different connection type propertities:

No.	connection type	Reliability(100)	Economic(50)	Convenience(50)	Total value:D=A*(B+C)%
		A	B	C	D
1	Bulging	100	48	50	98
2	V press	100	50	48	98
3	M press	95	45	45	85.5
4	Groove	95	40	45	80.75
5	Flange	100	40	50	90
6	Compression	95	45	45	80.5
7	Welding	95	50	25	71.25

Workability of different pipe fittings:                          

No.	Fitting Type	Construction Convenience	Construction Quality Control	Construction Wholesomeness	Product Imperceptibility	Destructiveness Wallboard	Connect Reliability	Global Evaluation
1	Bulging	Excellent	Easy	Excellent	Excellent	No	Excellent	Superior
2	V press	Excellent	Easy	Excellent	Excellent	No	Excellent	Superior
3	Compression	Excellent	Easy	Excellent	Able	Small	Excellent	Superior
4	Welding	Bad	Difficult	Bad	Unable	Small	Excellent	Middle and low level
5	Groove	Medium	Medium	Excellent	Unable	No	Good	Middle and low level
6	M press	Excellent	Easy	Excellent	Able	Small	Excellent	Superior