Guide
ASSE 1016, 1017 or 1070: which standard applies to a thermostatic mixing valve, and what does it ask of the machined parts?
A thermostatic mixing valve is a valve that blends hot and cold supplies to hold a set outlet temperature, and in North America the choice of ASSE product standard depends on where the valve sits and who can adjust it. ASSE 1016 covers shower and tub/shower valves with user controls, ASSE 1017 covers master valves at the hot water source, and ASSE 1070 covers temperature limiting devices for sinks, bidets, lavatories and tubs. This guide maps each standard to the part of the valve that reaches a shop drawing, and says plainly where the published text stops.
By Saola Manufacturing engineering team · Published · Updated
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Which ASSE standard covers which kind of temperature control valve?
Each standard is defined by location and by whether the user can adjust the temperature. 1016 is point-of-use with user controls, 1017 is at the hot water source, 1069 is fixed-setting for fixtures the user cannot adjust, and 1070 limits temperature at sinks, bidets, lavatories and tubs.
The wording comes from the standards listing on the ASSE International product standards page, which is undated and carries a 2026 copyright. ASSE describes itself as an ANSI-accredited developer of more than fifty product performance standards, with temperature actuated mixing valves among the best known (see the ASSE standards page). The table copies the scope statements for the five that buyers confuse most.
| Standard | Title | Where it applies |
|---|---|---|
| ASSE 1016-2017 | Automatic Compensating Valves for Individual Showers and Tub/Shower Combinations | Point-of-use valves where the user can reach flow or final temperature controls and no further mixing happens downstream: hand-held showers, shower heads, body sprays, tub spouts of tub/shower combinations |
| ASSE 1017-2023 | Temperature Actuated Mixing Valves for Hot Water Distribution Systems | Installed at the hot water source; not intended for point-of-use temperature limiting, including emergency eyewash and shower equipment |
| ASSE 1069-2020 | Automatic Temperature Control Mixing Valves | Individual or multiple fixtures where the user cannot adjust the temperature and no further mixing happens downstream, such as gang showers and sitz baths on a single preset supply |
| ASSE 1070-2020 | Water Temperature Limiting Devices | Limits hot or tempered water to fittings for sinks, bidets, lavatories and bathtubs to reduce scald risk; not designed to address thermal shock |
| ASSE 1071-2012 | Temperature Actuated Mixing Valves for Plumbed Emergency Equipment | Eyewash, eye/face wash and drench showers in systems that comply with ANSI Z358.1 |
How do you choose between 1016, 1017 and 1070 for a product?
Choose by location first, then by adjustment. A valve in the shower or tub/shower the user controls is 1016, a master valve for a hot water system is 1017, and a limiter feeding sinks, lavatories, bidets or tubs is 1070.
Three traps follow from the scope text. A 1017 valve is not a point-of-use limiter, so it cannot stand in for 1070 at a fixture. A 1070 device is expressly not designed for thermal shock, a risk that the 1069 scope text names as one it addresses. And emergency equipment has its own standard, 1071, tied to ANSI Z358.1.
The product owner decides this, and the machine shop does not. The shop’s practical need is to know which standard the finished valve will be tested to, and which edition, so that the drawing and the quote can name the same one. Standards are reaffirmed and revised on a cycle, so a drawing that says only “ASSE 1070” should name the year as well.
What do these standards ask of the machined parts?
The published scope text asks nothing of an individual part. It defines the finished valve and where it is used, and the performance numbers sit in the standards themselves, which ASSE sells.
This guide does not quote tolerances or temperature limits from any ASSE standard. The numbers for temperature control accuracy, shutoff and similar tests must be read from the edition your valve is tested to, and a statement of them in a blog post or datasheet should be checked against that edition before a drawing relies on it.
What can be said is how a standard reaches the shop. The valve maker turns the standard into functional requirements for each part, and the drawing carries them as fits, surface finish, geometric controls and materials. The parts named in this topic, thermostatic cartridge bodies, pistons or shuttles, seats, stems and inlet fittings, are all places where a requirement of that kind lands. That is our reading, and it is why the RFQ should ask for the functional requirement behind each tight feature.
Do the lead-free rules apply to the parts of these valves?
Sometimes: shower valves and tub fillers are exempt by name from the federal lead-free rule, while a limiter feeding a lavatory is not on the named list. The exemption belongs to the finished product and not to the standard.
The statute lists shower valves and tub fillers among the products that the lead-free prohibition does not apply to (see 42 U.S.C. 300g-6(a)(4)), and lavatory fittings are not on that list. This is general information, not legal advice, and the product owner’s compliance lead confirms any exemption. Our guide to the federal lead-free exemptions walks through the reading. Our guide to lead-free brass for NSF 61 and NSF 372 covers the alloys used where the rule does apply.
Even where a part is exempt, a valve maker may choose to keep one alloy across the family so that cartridge bodies and stems are interchangeable between exempt and non-exempt products. For bar stock, ASTM B927 includes C27450 among its alloys and ASTM B371 covers silicon-brass rod; see the B927/B927M-23 store page and our guide to brass bar call-outs for the paperwork.
Which machined features decide control accuracy, and how should they be drawn?
The sliding fits between piston, sleeve and body, the geometry of the seat and the alignment of the bores decide how well the valve holds temperature. Draw them with functional tolerances supplied by the valve designer, and not with numbers copied from a similar part.
A thermostatic valve moves a piston or shuttle against a thermal element, so friction, side load and leakage past the seat show up as drift in outlet temperature. These are the features worth controlling: diametral clearance of sliding members, surface finish of bores and seats, concentricity and squareness of seats to the bore axis, and the sharpness and cleanliness of cross-hole edges. We do not publish numeric tolerances here, because the valve designer holds the requirement and the standards hold the test.
On the drawing, use geometric controls with a datum scheme that matches how the valve is assembled, and ask for first-article results on the tight features before the lot is released. The CNC machining of such parts is handled by CNC turning and CNC milling at our lead CNC plant. Any plating, passivation or other finish on cartridge components is arranged through partner plants we manage, and a finish changes dimensions, so state the dimension that applies after finishing.
What documents should an RFQ ask for?
Ask for the alloy and bar specification, a mill certificate matched to the lot, a first-article dimensional report and a clear statement of which standard and edition the finished valve is tested to. The valve maker, not the machine shop, owns the standards test report.
A machine shop can support the valve maker’s test with the documents it controls: material test reports tied to a lot number, a dimensional report for the features named as critical, a cleanliness requirement agreed on the drawing, and traceability from bar to finished part. How the certificate types differ is covered in our guide to EN 10204 3.1 and 2.2.
It should not claim that the finished valve meets an ASSE standard on the strength of the parts alone. The standard is applied to the assembled product, and the proof sits with the party that tests it. A supplier who promises otherwise is promising something it cannot control.
Frequently asked
Is ASSE 1017 the right standard for a valve at a lavatory?
No. According to the ASSE listing, 1017 is installed at the hot water source and is not intended for point-of-use temperature limiting. Sinks, lavatories, bidets and tubs fall under 1070.
Does ASSE 1070 protect against thermal shock?
The ASSE listing says 1070 devices are not designed to address thermal shock. The 1069 scope text names scalding and thermal shock risk, and 1016 covers automatic compensating valves for showers.
What is the difference between ASSE 1016 and 1069?
1016 covers individual showers and tub/shower combinations where the user adjusts flow or temperature. 1069 covers valves for individual or multiple fixtures where the user cannot adjust the temperature.
Can a machine shop supply tolerances from the standard?
Only if the valve maker provides them from the edition it tests to. Do not copy numbers from datasheets or articles without checking the standard text.
Which edition should a drawing name?
The one the finished valve is tested to, with its year, for example the 2020 edition of 1070 or the 2023 edition of 1017 listed by ASSE. Name the edition so the quote and the drawing agree.
Sources
- ASSE International product standards (1016, 1017, 1062, 1069, 1070, 1071), ASSE International, page read October 2026, copyright 2026
- ASSE standards development, ASSE International, page read October 2026, copyright 2026
- 42 U.S.C. 300g-6, Prohibition on use of lead pipes, solder, and flux, Cornell Legal Information Institute, current text read October 2026
- ASTM B927/B927M-23, Brass Rod, Bar, and Shapes, ASTM International, 2023