How to do accumulator oil and nitrogen filling for guillotine shearing machine

How to fill nitrogen and oil for QC11Y guillotine shearing machine accumulator
QC11Y guillotine type hydraulic shearing machine has two hydraulic cyiders and an accumulator.The hydraulic cylinders drive the blade carrier down. The accumulator helps to drive the blade carrier back to top dead point. The air pressure of the accumulator should be 7-8Mpa.
Sometie, the blade carrier back stroke is very slow. Eenly the blade carrie cannot retun to top dea point. When thishappens, operator shall ispec he accumulatr ai resue ad oil pressure. 
This article is to introduce the nitrogen filling steps and oil filling steps. 

A: nitrogen filling steps
Firstly, prepare nitrogen botle and the nitrogen filling tool. The filling tool is normally shipped with the shearing machine.

Step 1: open the cover and the plug on the top of accumulator

Step 2: connect the filling tool with the accumulator and the nitrogen bottle

Step 3: open the valve on filling tool, then open the valve on the nitrogen bottle slowly

Step 4: close the valve on filling tool till the pressure gauge achieve at 8Mpa (refer to different model standard), close the valve on nitrogen bottle
Step 5: screw the pressure release switch on the nitrogen filling tool, till the pressure gauge back to 0

Step 6: move away the filling tool from the accumulator

B. oil filling steps
To filling oil into the accumulator, it needs two persons to work together.
Step 1: one person goes to back of the shearing machine. Find the valve with pressure gauge on the bottom of the accumulator. Open the valve.

Step 2: one person goes to the front the machine. Find the oil filing button on the control panel. Keep pressing the button and ask the back person to check the oil pressure gauge.

Step 3: Once the pressure arrives at 10Mpa (refer to different model standard, 10-20Mpa), the front side person stops prssingte oilfilling buton. A the same time, the back side person closes the valve immediately.