Cymap - Break a Leg!

By Gary Mann

In Cymap Mechanical Programs, once a pipe or duct has been placed, editing of the pipe position is limited to the following:

1. Dragging the emitter, grill or appliance which will reposition the connections as needed.
2. Editing a Radiator to a smaller or larger model can maintain the pipe connections.

Deleting a section of Pipe or Duct is also limited to an entire section e.g. from a Tee position to an entry point, or between a tee to a tee.  However, any Pipe or Duct can have an additional node inserted, resulting in a dividing split in the length, this enables editing of both sides of the node independently.

For example, in the screenshot below, Copper pipe has been selected to be the chosen pipe for the internal installation. The supply to the building has been run in MDPE (66 m) and changes via a straight connector located in the plant room.

To introduce a Breakpoint for the highlighted (in green) system above, choose; Insert>Gas System>Distribution Pipe.

Single click on the point which a break is required.  Then press Escape.

The single click operation is vitally important because it is often easy to double click out of habit as the “Double Click” is used to ‘Tee’ a pipe into an existing section.

Double clicking is not to be used when “Breaking a Leg” as it may insert a very short or negligible length of pipe at the break point. Short lengths of pipe require additional joints, are expensive to install and require extra sealing on site. These short lengths of pipe are known as “Washers”.

N.B. See the results of “Breaking a Leg” of the Entry section, approximately mid-room (N.T.S.).

It is displayed as a small square with a flow direction arrow close by.

I have also changed the External Pipe to MDPE at the break and added the extra external pipe length (66m) to avoid having a large DXF which contains nothing more than the entry pipe winding its way through the site. Note also that the pipe diameter has increased, though in this case not entirely due to the additional resistance of 66m of pipe, but that Ø42 is not available in that MDPE Range and the nearest appropriate size available is Ø50.

It is also interesting to note that I have added three additional bends. This is a common practice to allow for the pipe re-route to avoid unseen obstructions. However, I would suggest that if you had drawn the incoming mains routing around several obstacles, you could justifiably reduce the number of bends, because bends of long radius (Pulled Bends) have a much lower resistance to sharp bends created by fittings and are often of negligible frictional resistance.

The above is a very useful editing tool and can be used, not least, in the following examples:

• Fixing a section of existing pipe size by inserting a break and overriding the calculation.
• Inserting multiple Silencers in series into a length of Duct.
• Relocating the Entry Point to a different area of the building. Note that an entry point must be deleted before another can be connected to the same systems.
• Insulation is to be added or removed from a section of the network.

The above list is not exhaustive. Let me know if I have missed your favourite use.