When we think of steel flumes - whether they be Parshall, Cutthroat, or H type – we are concerned with both the high (stainless) and low (galvanized) end of the market. While fabrication techniques are identical, the applications for steel flumes differ.

Stainless Steel Flumes

At the high end of the market we have stainless steel flumes, which are suitable for the most demanding of applications. High temperature, corrosive, abrasive, or abusive environments are all ideal for the use of stainless steel. Stainless steel flumes are generally constructed in T-304 or T-316 alloys. Of the two, T-304 stainless steel is the more versatile and widely used.

Applications for T-304 stainless steel flumes include:

• High temperature
• Moderately corrosive (more than can be economically handled by Iso or Vinyl Ester fiberglass resins)
• Abrasive (grit, rocks, etc.)
• Abusive (accessible by the public)

While suitable for any application that T304 can be used in, the additional cost T-316 stainless steel tends to limit its use to applications requiring extreme corrosion resistance. These typically include:

• Salt water
• De-icing salts
• Brine solutions
• Industrial inter-plant flows

Should a stainless steel flume be used to measure sanitary flows, T-316 stainless steel should be used due to the corrosive nature of the flow stream and the water vapor associated with it – hydrogen sulfide being emitted by anaerobic decomposition of organic matter, which in turn leads to the formation of sulfuric acid.

T-304 stainless steel flumes tend to cost 25-50% more than a similar flume in fiberglass and T-316 stainless steel flumes tend to cost an additional 25%-50% above this.

Galvanized Steel Flumes

At the other end of the cost spectrum are galvanized steel flumes. Galvanized steel flumes are most commonly use on irrigation / water rights flows where there are relatively few sharp solids and where the flow is clean.

Galvanized steel flume prices vary due to the gauge thickness and craftsmanship, but in general, a galvanized steel flume is 15-33% less than the cost of a similar flume in fiberglass.

Galvanized steel flumes also resist impact damage better than fiberglass (think cattle walking on / near them), are easier to repair, and are suitable for applications where vegetative burn backs may occur.