Hypertherm PAC500 Water Injection Plasma Cutting System - Manual (Page 34)

PAC500 Instruction Manual 4-3
4
OPERATION
Nozzles have current limits and piercing limits that should not be exceeded. The piercing limit is lower than the
cutting thickness limit for the larger two nozzles. These limits are listed in the table above. Care should be taken
that the proper swirl ring is inserted for the nozzle in use. Use of an incorrect swirl ring will significantly reduce the
current handling capacity of a nozzle. Note that the three smallest nozzles (which are most commonly used) all use
the same swirl ring.
Swirl rings are not marked with any identifying marks due to their small size. The plastic containers in which they
are packaged are marked with the part number and the nozzle(s) with which they are to be used. Swirl rings may
be identified if not in the container by knowing the following:
1. There are three sizes of swirl ring.
2. The largest size has EIGHT .062 holes and is used only with the .250 nozzle.
3. The two smaller sizes have FOUR holes.
4. Of the two smaller swirl rings, the one with .032 holes is for the .120, .166 and .187 nozzles. The one with
the .052 holes is only used with the .220 nozzle.
Normally, the direction of gas swirl is clockwise. This clockwise swirling action causes the right hand side of the kerf
to be square and the left hand side to be bevelled; hence, it is important that the direction of travel be selected so
that the bevelled side is on scrap. For example, the outside diameter of a flange is cut with the torch traveling
clockwise, while the inside diameter is cut counterclockwise. This results in the flange having a high quality edge on
both cut surfaces as shown in figure 4, page 5-15. For applications which require the vertical side to be on the left
hand side of the cut, a counterclockwise (.032) swirl ring, Part No. 020042, should be used.
Two nozzle retaining caps are available:
Cadmium plated, Flared Retaining Cap......Part No. 020043
Brass, Tapered Retaining Cap ....................Part No. 020034
The flared retaining cap is designed to provide optimum performance of the Water-Muffler. The flared front end
produces a thicker, more stable water curtain thereby improving sound attenuation. This retaining cap also
Table I
Nozzle Thickness Ranges and Limits
Nozzle Swirl ring Thickness Current Piercing
Size Part No. Size Part No. Range Limit Limit
********** ********** (inches) (amperes) (inches)
.120 020050 .032 020039 .035 – 1/4 260 1/4
.166 020035 .032 020039 1/8 – 1 400 1
.187 020036 .032 020039 1/2 – 2 600 1-1/2
.220 020037 .052 020040 2 – 3 750 2
.250 020047 .062 020048 3 – 5 1000 Not Permitted
Note: The .250 Nozzle is for conventional cutting only. It must be used only with the Argon-Hydrogen Manifold.