Typically, "mmSS" refers to millimetres of a water column under standard conditions; it can also be written as mmWC or mmH₂O. Since both refer to the pressure applied by a water column of that height, in actuality, mmSS equals mmWC.
You can therefore interpret 200 mmSS as 200 mmWC if your customer wrote it that way (no actual conversion factor needed).
👉 If precision is crucial, simply ask them to confirm that "SS" stands for "water column at standard state," even though in engineering terminology it's synonymous with mmWC.
| Current Thread... | |
| 07/19/2024, 5:27 AM | UNIT OF PRESSURE FOR GAS |
| 09/17/2025, 12:22 PM | Re: UNIT OF PRESSURE FOR GAS |