tongshun supply professional and honest service.

Your water system is vulnerable to a wide array of potential issues, from Legionella bacterial overgrowth to rust and sediment. Creating a proper water treatment plan that addresses these risks comprehensively requires more than just guesswork; you will need to conduct testing to understand what vulnerabilities your system is facing. One such option is the use of corrosion coupons. If this term is unfamiliar to you, or if you are just looking into using coupons to better understand the health of your water system, continue reading to learn more about how this diagnostic approach works.

What Is A Corrosion Coupon?

A corrosion coupon is a material that is used to determine how corrosive your water is&#;and by extension, how much damage your pipes may be suffering as a result. Typically, this coupon takes the form of a small metal piece (often in the shape of a coupon, hence the name) that is affixed within your water system so that the water can flow freely past it for a set period of time.

After that time, you can remove the coupon and see how it has reacted to your system&#;s water; this will give you an indication of what your pipes are experiencing and how to remedy the situation. If it is corroded, you can expect some corrosion damage on your pipes, too.

Benefits Of Corrosion Coupon Monitoring In Your System

Corrosion coupon monitoring can provide valuable insight into the acidity and other elements of your water without having to completely remove a segment of piping in order to check its durability and condition. Identifying corrosion as soon as possible is vital so that you can avoid premature repair and replacement of critical equipment; corrosion can cause not only leaks that cost you money in water damage and higher water bills, but it can also contribute to inadequate performance of your machinery.

If you operate cooling towers, for example, corrosion may impact how heat is exchanged. Corrosion coupon monitoring is a simple and effective way to gather important data about your system so that you can make a plan.

How To Properly Set Up A Coupon

Setting up a corrosion coupon is not as simple as just placing it into a pipe. Instead, you must be strategic about where it is located so that you can gather the most relevant data about your system. A professional can help you to identify the most appropriate location for your coupon if you need assistance.

Duration

One of the most important aspects to decide when you are installing a corrosion coupon is how long you will test. While it is possible to test for only 30 days, this may produce results that are more difficult to learn from. Instead, the recommended time frame for corrosion coupon monitoring is at least 90 days, though you may continue for longer if needed.

Placement

Coupons should be placed so that water flows from the holder (rather than toward it), and they should be located differently depending on the material you are testing. Follow the galvanic series; the most active metal should be placed first so that unwanted metal deposits do not cloud the results.

Flow And Environment

In order to procure accurate results, water flow past the corrosion coupon should not dip below three feet per second, up to a maximum of five. Any faster could result in erosion of the material, which will cloud the results of the test. Place your coupon in the area with the warmest water, as cool water can artificially lower the rate of corrosion.

Things To Avoid

Never couple your corrosion rack to valves made of galvanized steel or brass. These materials will react with the corrosion coupon setup through the release of copper or zinc ions that will skew the results. Copper ions will accelerate corrosion, and zinc ions may synergize to artificially create a layer of protection against corrosion that is not present in the entire system, leading to the false belief that your system is safe from corrosion.

Trust The Experts To Help You Manage Your Water System Effectively

Whether you are just hearing of corrosion coupons for the first time or you are ready to install them but are not sure how to do so by yourself, trust the experts. The professionals at Tower Water set the standard in water treatment and would be happy to help you identify the proper location and usage for your corrosion coupons so that you can gather relevant data. Reach out to learn more or to schedule an appointment to achieve your water treatment goals.

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Lost hot tap coupon in a pipe

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Lost hot tap coupon in a pipe

Lost hot tap coupon in a pipe

seasar

(Mechanical)

(OP)

10 Jan 12 17:29

Had a bit of an oops moment earlier when contractor were performing a hot tap on a glycol line in that the pilot bit broke
off and the coupon dropped into the pipe.  The next thing the pipe
does is run 50 ft up.  Are there any rules of thumb for velocity
required to carry an object through that situation?  If the coupon sits at the bottom of the elbow prior to the run up for eternity I'm happy...and that is what I expect it do based on gut feel but something to confirm that would be nice.

Any advice?  Can't imagine I'm the first person in this situation.  Thanks!

Replies continue below

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RE: Lost hot tap coupon in a pipe

MiketheEngineer

(Structural)

10 Jan 12 17:53

Kinda depends on the area, weight and flow volume.  Sorry - no help here.

RE: Lost hot tap coupon in a pipe

seasar

(Mechanical)

(OP)

10 Jan 12 17:54

As an update...this is 32% propylene glycol at 30F.

 

RE: Lost hot tap coupon in a pipe

Duwe6

(Industrial)

10 Jan 12 18:57

What are the diameters of the "cookie" and the line?  Is the cookie SCH40 or 80?

RE: Lost hot tap coupon in a pipe

seasar

(Mechanical)

(OP)

10 Jan 12 19:04

2 3/8" Cookie...10" line...sched 40.

Velocity in the line doesn't exceed 3 fps.

My rule of thumb is that the velocity required to lift an object in a situation like this must be greater than the free fall velocity it would experience in a stagnant line.

RE: Lost hot tap coupon in a pipe

MiketheEngineer

(Structural)

11 Jan 12 11:30

At 3 fps - my guess is that it is sitting at the bottom of the elbow and not likely to move.  

RE: Lost hot tap coupon in a pipe

Duwe6

(Industrial)

11 Jan 12 13:28

Agree with

Mike

, it will not make it up the 50-ft rise.  As

seasar

points out, the flow velocity has to be similar or larger than the free-fall velocity.  You could try an experiment using a 10-ft tall 10-inch riser and a fire hose.  Should prove that the cookie will stay near the bottom ell.

RE: Lost hot tap coupon in a pipe

cvg

(Civil/Environmental)

11 Jan 12 14:04

strap a magnet on the elbow

RE: Lost hot tap coupon in a pipe

racookpe

(Nuclear)

14 Jan 12 23:54

At the elbow, remove the (external) insulation.  Put a good-sized magnet on the lower surface of the elbow, and move it back and forth.  You might be able to hear the coupon sliding back and forth inside the pipe.   That doesn't get it out of the pipe, but it will tell you where it is.   

Xrays of the pipe will confirm the location - at a higher price.

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