Welcome to All Sensors “Put the Pressure on Us” blog. This blog brings out pressure sensor aspects in a variety of applications inspired by headlines, consumer and industry requirements, market research, government activities and you.
Another PSI Sighting: Pressure Shows Up Everywhere
While I could be more sensitive than many other people, any indication of the need to measure and/or control pressure in everyday situations usually catches my attention. A recent observation was the number on a neighborhood fire hydrant – in big letters it stated 200 psi. It turns that this is a common working pressure design criteria for residential fire hydrants.
Conducting flow and pressure testing measurements require a pitot gauge and a fire hydrant cap gauge. Pressure measurements on fire hydrants are performed primarily using analog gauges with a 0 to 300 psi range although digital instruments do exist with one digital gauge specifying 0.5% accuracy. Static pressure is the normal pressure existing on a system before the hydrant flow valve is opened. Local requirements vary but in one case, normal minimum water pressure in a distribution system cannot be below 35 psi when a fire hydrant is opened downstream and the minimum water pressure (residual psi) cannot be below 20 psi. Observed pressure requirements include: 75 psi for larger cities and 50 psi for smaller cities.
In addition to the pressure range and accuracy, environmental aspects for a fire hydrant pressure sensor include the ability to withstand the contact of water and possibly other materials. Properly specifying the “designed for” and other operating pressures and environmental requirements are just the beginning of getting the right pressure sensors for testing fire hydrants or measuring the pressure of any flowing/static liquid.
What do you think/Comments?
Do you have a pressure sensing question? Let me know and I’ll address it in an upcoming blog.
-Dan DeFalco, Marketing Manager, All Sensors Corporation (firstname.lastname@example.org)