Jumping pipework

[multisync]

We have a 3 pipe VRV (old R22) which seems to emit a loud bang every now and again.

It appears the pipes enter the building and drop 500mm to the tray then along. The maintenance man has seen these pipes jump off the tray and back with the loud bang mentioned.

We assume it's oil recovery or defrost type event. None of the pipework is clamped anywhere and we wonder if this is common and can we cable tie the pipes to the tray (around the armaflex) to stop thios happening

What is the recommended guide line to stop this

[VRVIII]

We have a 3 pipe VRV (old R22) which seems to emit a loud bang every now and again.

It appears the pipes enter the building and drop 500mm to the tray then along. The maintenance man has seen these pipes jump off the tray and back with the loud bang mentioned.

We assume it's oil recovery or defrost type event. None of the pipework is clamped anywhere and we wonder if this is common and can we cable tie the pipes to the tray (around the armaflex) to stop thios happening

What is the recommended guide line to stop this

Bigger cable ties :D

[multisync]

Bigger cable ties :D

Actually there are no cable ties and haven't been for years.However we will return and tie the pipes down. Strange there are 6 systems on site and only this one has ever caused a noise problem..

Thanks for the advice:D

[DEVIL]

Did it do this before ?

If the amount of refrigerant is overcharged (or other malfunction) you might get liquid back to compressor and that would do enought vibration and make the pipe do this behavior

[VRVIII]

Actually there are no cable ties and haven't been for years.However we will return and tie the pipes down. Strange there are 6 systems on site and only this one has ever caused a noise problem..

Thanks for the advice:D

I was joking Multi, but don’t suppose the cable ties would do any harm :D
I’ve never heard of VRV pipe work jumping before, do you know if it’s all 3 pipes or one in particular? I was surprised to find that ever 20m of pipe work can have up to 17mm of thermal expansion/contraction.
It could also be due to a faulty or sticking valve or something alone those lines.

[multisync]

I was joking Multi, but don’t suppose the cable ties would do any harm :D
I’ve never heard of VRV pipe work jumping before, do you know if it’s all 3 pipes or one in particular? I was surprised to find that ever 20m of pipe work can have up to 17mm of thermal expansion/contraction.
It could also be due to a faulty or sticking valve or something alone those lines.


We haven't seen it but one of the maintenance guy's has. :)

I will ask them again for more details which may id the pipe or pipes..There are no complaints of poor performance

[multisync]

Did it do this before ?

If the amount of refrigerant is overcharged (or other malfunction) you might get liquid back to compressor and that would do enought vibration and make the pipe do this behavior

For many years we were told today:cool:

[DEVIL]

pipe dilatation is not the case, we only add dilatation compensator if we exceed 70 m if it's straight and depending on the pipe diameter.
But dilatation doesn't make visible movements , or if it's visible it just moves slow not jumping.

The only cause i see is vibrations from the outdoor unit, and that is mainly made by liquid pumping and as shocks like elbows there is the place they make them-selfs more visible