Rectangle ventilation door
Rectangle ventilation door closed with a strip in the housing to limit, to fully open the use of before and after the bearing bolts for the limit. Side throttle a uniaxial, biaxial, triaxial, axis and axis of five forms of the preparation of 300 × 400-2400 × 2000 hand, the electric specifications of all 66 species. Electrical device supporting damper with electric park.
Specification for Rectangle ventilation door:

图号	公称通径	L1	L2	L3	L4	L5	L6	I	d	螺杆孔数(n)	重量Kg
	mm
DD4201	300×400	390	460	526	300	360	436	124	14	18	55.7
DD4202	300×500	490	560	626						20	64
DD4202	300×600	590	660	726						22	70
DD4204	300×700	690	760	826						24	72.4
DD4205	400×500	490	560	626	400	460	536			22	72
DD4206	400×600	590	660	726						24	78.9
DD4207	400×700	690	760	826						26	85
DD4208	400×800	790	860	826						28	100
DD4209	500×600	590	660	726	500	560	636			26	85
DD4210	500×800	790	860	926						30	142
DD4211	500×900	890	960	1026						32	146.7
DD4212	500×1000	990	1074	1126					18	38	128