Blog

In its simplest form a Packaged Metering Manhole (PMM) consists of a primary device (typically a flume or weir) molded into a fiberglass (FRP) manhole.  By directly factory integrating the primary device, a single-piece, drop in-place flow monitoring solution is…

For applications where the depth of a Packaged Fiberglass Manhole has been undersized, Openchannelflow offers Manhole Extensions.  These Extensions are designed to provide standardized solution integrating the height modification, top, and ladder into a single drop-in-place…

One of the problems contractors often face when installing a flume in a concrete manhole is forming the transitions into / out of the flume.  Done poorly and the result is a flume that either experiences turbulence or submergence – both which will seriously compromise…

The traditional method of measuring wastewater flows is through the use of a flume and an ultrasonic flow meter in a flow manhole (concrete vault / manhole or fiberglass packaged metering manhole).  The combination is reliable and usually requires low maintenance.

The old adage of taking  measuring twice and cutting once has never been so appropriate as it is when determining the depth of a fiberglass manhole.  Although fiberglass (FRP) manholes posses a wealth of benefits; modularity is not one of them.  Because all of the…

Fiberglass Diversion Manholes are way of controlling open channel flows in a factory integrated design.  Utilizing the core design of standard Flow Metering Manholes, Diversion Manholes provide corrosion resistance, speed of installation, and ease of use.  Dig It!…

One of the oft-mentioned benefits Packaged Metering Manholes is the ability to integrate flumes and other structures that are larger than the manhole barrel diameter, but what exactly does this mean?

As we’ve seen before in our comparison of H-flume and Parshall flume manufacturers, not all “equal” products are just that…equal. Here we compare the construction details of Packaged Metering Manholes.  Packaged Metering Manholes take proven open…

Let’s be honest:  metering manholes (from an upfront, material cost standpoint) aren’t cheap.  While no one would argue that metering manholes don't provide substantial benefit to their users, part of what you are paying for is a unit that is ready for…

With Free Flow, Inc. (formerly of Gretna, NE) closing last year, Openchannelflow would like to extend a welcome to its former customers who are in need of assistance with their flow monitoring needs. Free Flow was primarily know for three product lines: Flumes (Parshall /…

For many engineerings and end-users the default configuration for flume always includes a stilling well...and why not?  When they work, they work great - providing a convenient area to measure the flow in a flume.  When they don't work....well that's another…