FAQ - Frequently Asked Questions

When the displayed value for the regulator (1), which is attached to the argon gas cylinder (hereinafter, the cylinder), becomes 2 MPa or less, replace the cylinder. 

If air enters into the piping during cylinder replacement, argon gas will mix with air resulting in poor emission performance. In this case, it will take much longer for the analysis values to stabilize.
Replace the cylinder with the following procedure. (For the step numbers (1) to (3), see the reference piping diagram on the next page.)

 

CAUTION: Residual pressure for the cylinder should not be “0”. If it is “0”, there is a risk of air entering into the cylinder or piping.

 

1. Open the main valve (2) for full cylinder No. 2.

2. Shut off the main valve (2) for empty cylinder No. 1 and the main cock for the cylinder No. 1.
3. Connect the regulator (1) to the cylinder No. 1 to be replaced.
4. Open the main cock for the cylinder No. 1.
5. Open and close the valve (3) for purging cylinder No. 1 for a couple of times to discharge soiled gas in the piping.

6. Shut off the valve (3) for purging the cylinder No. 1.

NOTE:

  • If nitrogen is included in the elements for analysis, take extra care when replacing the cylinder.

  • When replacing the cylinder, take care not to let the dust in the piping.

  • Check residual pressure of the cylinder every day, and when it is under 2 MPa, replace the cylinder.

  • Keep the cylinder and regulator connected together.
    Leaving the regulator for long periods may cause the dust or water to enter into the piping.

(1) For argon gas Regulator: Pressure on the high pressure side: 15 MPa (150 kgf/cm²), Outlet pressure: 140 to 200 kPa (1.4 to 20 kgf/cm²)
(2)Main valve: Use a stainless steel type only.
(3)Leak valve: Used for air leaking from the piping when replacing the cylinder.

(4)Piping:  If the distance between the instrument and argon gas cylinder is within 5 m, use a polypropylene tube.
    If the distance between the instrument and argon gas cylinder is within 5 to 40 m, set the argon gas pressure in the midstream to 500 kPa (5 kgf/cm²) and install a regulator in the room as marked with ★ in the above diagram.
      • Stainless pipe for high purity gas Inner diameter: 6 mm
      • For the pipe diameter and installation method, consult an expert installation subcontractor.

      Reference: For the parts such as tee joint or elbow, an interlocking type may be convenient.