HOSE AS 7I5828 - Caterpillar

Illustration 1 g00738507
Carry-check valve (1) Passage to other carry-check valve (2) Orifice in check valve (3) Oil passage to the control valve and from the control valve (4) Vent passage to scraper control valve (5) In-line check valve (6) Check valve (7) Spring chamber (8) Passage to the rod end of the bowl cylinder
Illustration 2 g00739625
(9) Carry-check valveThe carry-check valves for the bowl cylinders will keep the bowl in any position when the bowl valve stem in the scraper control valve is in the HOLD position. When the bowl valve stem is in the HOLD position, the oil in spring chamber (7) is blocked and check valve (6) can not open. The oil in the rod end of the bowl cylinder is now trapped at passage (8) and the bowl cylinder can not move.The vent line for the check valve (6) is open to the hydraulic tank only when the bowl valve stem is in the LOWER position. The pump oil from the scraper control valve flows to the head end of the bowl cylinder. The oil in the head end moves the piston and the rod which is connected to the bowl, outward. The piston moves the oil from the rod end of the bowl cylinder through passage (8). The oil under pressure from the rod end of the bowl cylinders opens check valve (6). The oil in the spring chamber (7) flows through in-line check valve (5) and the vent line to the scraper control valve. In-line check valve (5) prevents oil from flowing back into spring cavity (7) and closing check valve (6). The oil from the rod end flows through the open check valve (6). The oil then flows through the opening (3) to the scraper control valve and the hydraulic tank.When the bowl valve stem is moved to the RAISE position, the pump oil from the scraper control valve flows through passage (3). The pump oil then opens check valve (6). The check valve (6) opens because the pump oil has more pressure than the pressure of the oil in spring chamber (7) and the rod end of the bowl cylinder. The oil in spring chamber (7) flows through orifice (2) when check valve (6) is opened by the pump oil.The pump oil flows through check valve (6) and through passage (8) into the rod end of the bowl cylinder. The pump oil moves the piston and the rod which is connected to the bowl, upward. The piston moves the oil from the head end of the bowl cylinder through a line to the scraper control valve and the hydraulic tank.