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By Peter Gobis III
Sort of like when Facebook started, we knew it was there, but we didn’t quite understand the gravity and impact that it was going to have. So goes it with “lead free” and mixing valves!
Back in September 2006, California signed into law Assembly Bill 1953, and that law set into motion the foundation and momentum that ultimately lead to the amending of The Reduction of Lead in Drinking Water Act. The new requirements for lead free went into effect on January 4, but there still exist some confusion on its applicability to mixing valves and other products in the commercial plumbing industry. With that said, let’s take some time to try and remove the confusion and understand the types of mixing valves in the market, the new lead free requirements and how it all mixes together.
To understand the various types of mixing valves used in today’s plumbing designs, we’ll reference the applicable ASSE performance standards for each. There are five core ASSE standards that define the performance requirements for mixing valves used in commercial plumbing installations. The first is ASSE 1016 (Automatic Compensating Valves for Individual Showers and Tub/Shower Combinations). These are devices intended to control the water temperature to wall mounted showerheads either in individual shower or tub/shower combination fixtures in order to reduce the risk of scalding and thermal shock. The three types of shower valves are pressure-balanced, thermostatic or a combined pressure-balanced/thermostatic; with pressure-balanced being the most commonly used in the industry.
Master Mixers is the next category and these are typically used to temper the stored hot water to safer temperature for distribution to the domestic hot water system. The requirements for these valves are stated within ASSE 1017, with one of the key testing criteria being the Temperature Control Test. This portion of the testing defines the permissible temperature variation above or below the set, with the tightest tolerance being +/- 3°F for valves that flow 3-5 GPM at 10 psi.
ASSE 1069 is the next standard and these are devices that are intended to control the water temperature in individual or multiple fixtures to reduce the risk of scaling and thermal shock. The testing here is similar to that of a shower valve. But, this mixing valve is intended to be installed where the bather has no access to the temperature adjustment means, and where no further mixing occurs downstream of the device. These types of mixing valves are used in applications such as gang showers and sitz baths.
Code requirements have lead to the next type of mixing valve being a staple in all commercial designs; ASSE 1070. In 2006, the International Plumbing Code was revised to state that “Tempered water shall be delivered from public hand-washing facilities. Tempered water shall be delivered through an approved water-temperature limiting device that confirms to ASSE 1070…”
This change has dramatically change the landscape for this product segment and these types of mixing valves are being used in lavatory application to limit the hot water temperature that is being delivered to the faucet, with a typical outlet temperature of 110°F.
The final category of mixing valves is emergency mixing valves, which must adhere to the testing requirements of ASSE 1071. These devices are used with emergency equipment, such as eye wash or drench showers that are intended to be installed in systems that comply with ANSI Z358.1. One of the most critical parameters of this standard is the hot water shut-off test. The purpose of this test is to verify that the device, when subjected to a sudden loss of hot water, shall continue to flow at a pre-determined rate.
Now that we are all mixing valve experts, let’s understand the changes to the Reduction of Lead in Drinking Water Act. The core to the lead free changes were redefined in Section 1414(d), which lowered the maximum lead content of the wetted surfaces of plumbing products such as pipes, pipe fittings, plumbing fittings and fixtures from 8 percent to a weighted average of 0.25 percent or less. Well that makes the potential product scope clear as mud doesn’t it? There was certainly confusion when the revision was enacted and that is why the EPA released a “Summary and Frequently Asked Questions” document in October 2013. This document addressed some of the vague language used within the act; such as what is “potable services”. The EPA interpreted “potable services” to be services or applications that provide water suitable for human ingestion (e.g. drinking, teeth brushing, food preparation, dishwashing, maintain oral hygiene).
In reading this interpretation of “potable service,” it makes one question if mixing valves would have to be designed to meet the new lead free requirements. If you think about commercial applications, the various types of mixing valves we discussed are all essentially used to temper water for either hand washing or shower applications and for not potable service. But, we now have to consider the domestic hot water system as a whole and one key component – recirculation!
Recirculation is used in commercial applications to maintain the domestic hot water loop temperature during periods of no demand. Hot water is typically stored at 140°F to help deter the growth of bacteria’s that are normally present in water supplies (e.g. legionella pneumophila). This is then tempered with an ASSE 1017 master mixer to around 120°F and distributed to the building for hand washing and shower applications. The unused tempered water is returned and through the use of a balancing valve and some amount of that return water is sent back to the mixing valve (either to the cold supply or via a designated return connection) while some amount is returned to the hot water source.
So how does this recirculation system then draw mixing valves into having to be lead free? This is addressed by EPA’s FAQ’s #13. This question asks if a product is sold for use in non-potable services but it could be connected to a potable service, does it have to comply with the law. This is the key!
Going back to our installation scenario, tempered water that passed through a mixing valve is then returned to the hot water source, and that 140°F water could then be sent to a kitchen. That 140°F water could be used for food preparation and thus, the mixing valves are connected to the higher temperature loop and food preparation, which was interpreted to be within the scope of potable service. Do you feel like your back in kindergarten? “The knee bone is connected to the thigh bone!”
Now that we understand that mixing valves have to comply with the lead free requirements, I have to throw a curve ball at you and there is an exception. Within the Act, Section 1417 (a)(4) states that some products are actually excluded from the law. They exclude “toilets, bidets, urinals, fill valves, flushometer valves, tub fillers, shower valves, service saddles, or water distribution main gate valves that are 2 inches in diameter or larger.” So, what is the bottom line? All mixing valves should conform to the lead free requirements with the exception of ASSE 1016 shower valves, and any mixing valve that is not connected to a potable water service.
Many companies, like Leonard, have made the transition to provide quality products that are third party approved as lead free. It is imperative that engineers review to verify that the products that they are specifying have been tested and approved to the lead free requirements. Leonard is committed to improving the quality of our product by using robust materials of construction, like stainless steel, to meet the 0.25 percent or less threshold. Engineers can rest assure that our ECO-MIX line of mixing valves have all been third party approved to lead free but, you should always verify with either IAPMO or ASSE to confirm which products in the industry are third party approved as lead free and meet their respective ASSE performance standards.
Peter Gobis III is national sales manager for Leonard Valve Company.