What Is an ASCO Solenoid Valve?

A solenoid valve is an electrically actuated valve — when voltage is applied to the coil, it generates a magnetic field that opens or closes the valve. Remove the voltage and a spring returns it to its default position.

ASCO's Red Hat series is the most specified solenoid valve line in industrial controls. The right series depends on five variables: pipe size, what's flowing through it, operating pressure, supply voltage, and whether you need the valve open or closed when de-energized.

Get those five answers and you can spec any ASCO valve in minutes. Here's how to work through each one.

The 5 Questions That Spec Every ASCO Valve

These are the exact questions we ask on every call. Answer all five and the right valve falls out of the selection guide automatically.

Question 1
What is the pipe size?
Question 2
What is the media?
Question 3
What is the pressure?
Question 4
What is the voltage?
Question 5
N/O or N/C?
1

Pipe Size

This is your starting filter — it immediately narrows the field. ASCO solenoid valves are available from 1/8" miniature to 3" and larger. Most HVAC, boiler, and light industrial applications fall between 1/4" and 1-1/2". All connections are standard NPT female thread unless otherwise specified.

1/8" – 1/4"3/8" – 1/2"3/4" – 1"1-1/4" – 1-1/2"2" – 2-1/2"3"+
2

Media — What Is Going Through It?

The media determines which body material, seal type, and series is appropriate. Air and inert gas are the most forgiving. Water, steam, fuel gas, light oil, and corrosive fluids each have specific requirements. Never assume — the wrong seal material in the wrong media will fail quickly.

Air / Inert GasWaterFuel GasSteamLight OilHot WaterCorrosive FluidsOxygen / Special
3

Operating Pressure

Most standard ASCO 8210 series valves handle up to 150 psi on water and 300 psi on air. Above that you move to the 8223 high-pressure piston series, which handles up to 1,500 psi. For very low or zero minimum differential pressure applications, a direct-acting valve like the 8262 is required — pilot-operated valves like the 8210 need a minimum pressure differential to operate.

0 – 150 psi (standard)150 – 300 psi (air/gas)300 – 1,500 psi (high pressure)Zero pressure differential needed
4

Voltage

The most common voltages in the field are 120V/60Hz AC and 24V DC. ASCO offers coils in a wide range of AC and DC voltages. It's important to match the coil voltage exactly to your control circuit — wrong voltage will burn out the coil or fail to actuate. Next-generation ASCO coils support voltage ranging across 100–120V and 200–240V AC, which reduces the number of coil part numbers you need to stock.

120V / 60Hz AC24V DC240V / 60Hz AC12V DC24V ACOther voltages available
5

Normally Open or Normally Closed?

This is the valve's fail-safe position — what it does when power is removed. Most shutoff applications use normally closed. See the full N/O vs N/C explainer below.

Normally Closed (NC) — most commonNormally Open (NO)

Have Your 5 Answers? We'll Find Your Valve.

Tell us pipe size, media, pressure, voltage, and N/O vs N/C — we'll get you to the right part number fast.

Get Expert HelpCall (901) 458-2000

Normally Open vs Normally Closed — Explained

This trips up more people than any other spec question. The terms describe the valve's state when de-energized — not when it's running normally in your system.

Normally Closed (N/C)

The valve is shut when no power is applied. Energize the coil and the valve opens. Remove power and it closes automatically via spring return.

This is the most common configuration for shutoff, safety, and on/off control applications — if power fails, the valve closes and flow stops.

Common uses: Gas shutoff, water supply control, safety shutoff valves, burner fuel trains

Normally Open (N/O)

The valve is open when no power is applied. Energize the coil and the valve closes. Remove power and it opens automatically via spring return.

Used when flow must continue during a power failure — for cooling water, pressure relief, or fail-safe open applications.

Common uses: Cooling water, vent valves, applications where flow-on-fail is required

Quick rule of thumb: If losing power should stop flow → use N/C. If losing power should allow flow → use N/O. When in doubt, call us — getting this wrong is an expensive mistake.

ASCO Series Breakdown — Every Major Line

Once you've answered the five questions, here's which series you're looking at.

General Service · Most Commonly Specified
ASCO 8210 Series Red Hat®
The Red Hat Workhorse
Air / GasWaterLight OilMost Popular

The ASCO 8210 is the most widely specified general service solenoid valve in industrial controls. It's a pilot-operated 2-way valve available in brass or 304 stainless steel bodies, handling air, inert gas, water, and light oil across pipe sizes from 3/8" to 2-1/2". If someone says "ASCO valve" without specifying a series, they're probably talking about an 8210.

Most 8210 variants require a minimum 5 psi pressure differential to operate — if your system cannot guarantee that, move to the direct-acting 8262. The 8210 can be mounted in any direction and carries RedHat II enclosure ratings (Types 1, 2, 3, 4, 4X standard; explosion-proof Types 7 and 9 optional). Lead-free brass versions are available for potable water applications complying with the Safe Drinking Water Act.

Choose the 8210 when: General service air, water, or gas control, standard industrial or HVAC applications, pipe sizes 3/8" to 2-1/2", or any application where the 8210's proven platform and broad availability are priorities.

3/8" – 2-1/2" NPT
Air, Gas, Water, Light Oil
Up to 300 psi (air)
Brass or 304 SS
N/O or N/C
RedHat II / Exp. Proof Opt.
Need an 8210 series valve?Request a Quote →
Fuel Gas Shutoff & Vent Service
ASCO 8214 Series Red Hat®
The Gas Safety Shutoff Valve
Fuel GasSafety ShutoffUL / FM / CSA

The ASCO 8214 is built specifically for fuel gas shutoff and vent valve service on commercial and industrial gas burners. While the 8210 can handle gas in general service applications, the 8214 carries the UL, CSA, and FM safety shutoff valve approvals required under NFPA 54, NFPA 85, and insurance carrier requirements for gas burner fuel trains.

Available in sizes from 3/8" to 3" with normally open (vent valve) or normally closed (shutoff valve) configurations. The normally open vent configuration is required in many dual-shutoff fuel train designs where the vent valve must prove open between the two main shutoff valves before burner light-off is permitted.

Choose the 8214 when: Your application involves fuel gas on a commercial or industrial burner, your fuel train requires UL/FM-listed safety shutoff valves, you need a vent valve between main safety shutoff valves, or your insurance or NFPA compliance requires listed gas valves.

3/8" – 3" NPT
Fuel Gas Only
UL, CSA, FM Listed
N/O (vent) or N/C (shutoff)
Gas Burner Fuel Trains
NFPA 54 / NFPA 85
Specifying an 8214 for a burner fuel train?Request a Quote →
High Pressure Service — Up to 1,500 psi
ASCO 8223 Series Red Hat®
The High Pressure Piston Valve
High PressureAir / Gas / WaterHydraulic

The ASCO 8223 uses rugged piston construction to handle system pressures up to 1,500 psi — far beyond what standard diaphragm or pilot-operated valves can manage. When your application exceeds the pressure ratings of the 8210 series, the 8223 is the standard ASCO answer.

Available with electronically enhanced, intrinsically safe, non-incendive, and low power coil options for hazardous location installations. Stainless steel body versions are available for corrosive media or stringent cleanliness requirements. The 8223 also comes in 3-way configurations for cylinder or actuator control applications.

Choose the 8223 when: Your operating pressure exceeds 150–300 psi, you're working with hydraulic circuits, high-pressure compressed air, or high-pressure gas systems, or your application requires a listed valve for hazardous locations at elevated pressures.

1/4" – 1" NPT
Up to 1,500 psi
Piston (rugged duty)
Air, Gas, Water, Hydraulic
Brass or Stainless Steel
IS, NI, Low Power, EEx
High-pressure application? 8223 is your valve.Request a Quote →
Miniature & Direct Acting — Zero Pressure Differential
ASCO 8262 Series Red Hat®
The Miniature Direct-Acting Valve
Direct ActingZero Min Pressure1/8" – 3/8"

The ASCO 8262 is a direct-acting poppet valve — unlike the pilot-operated 8210, it doesn't rely on line pressure to operate. This makes it the right choice for zero or very low pressure differential applications, vacuum service, or any installation where the 8210's minimum pressure requirement can't be met.

Available in 1/8" to 3/8" pipe sizes in brass or stainless steel, with NBR or PTFE seals for a wide range of compatible media. The direct-acting design provides positive shutoff even at zero pressure differential. The 8263 variant adds hot water and steam capability for higher temperature applications.

Choose the 8262 when: You need zero minimum operating pressure, pipe size is 1/8" to 3/8", your application involves vacuum service, or you need a compact direct-acting valve with tight shutoff regardless of upstream pressure conditions.

1/8" – 3/8" NPT
Direct Acting (Zero ΔP)
Air, Gas, Water, Light Oil
150–180 psi typical (construction-dependent)
Brass or Stainless Steel
NBR or PTFE
Small pipe or zero pressure differential? 8262 is your call.Request a Quote →
Steam & Hot Water Service
ASCO 8220 / 8263 Series
The Steam & Hot Water Valve
SteamHot WaterHigh Temp

Standard ASCO 8210 valves are not rated for steam service — high temperature breaks down standard NBR seals quickly. The 8220 series is purpose-built for steam and hot water applications, with high-temperature seals, specially selected body materials, and coil insulation rated for elevated ambient temperatures.

The 8263 extends the miniature 8262 platform to steam and hot water service for smaller pipe sizes. Both series handle saturated steam and hot water up to the series-rated maximum fluid temperature, which varies by construction reference — always verify the specific catalog number's temperature rating against your application.

Choose the 8220/8263 when: Your media is steam or hot water above standard temperature limits, you're controlling boiler feedwater, steam supply, condensate return, or any high-temperature liquid or vapor application.

Steam & Hot Water
3/8" – 2-1/2" NPT
1/8" – 3/8" NPT
High-Temp Rated
Brass or Stainless Steel
Do NOT use 8210 for steam
Steam or hot water application? Don't use a standard 8210 — call us first.Request a Quote →
Potable Water & Lead-Free Compliant
ASCO 212 Series
The Lead-Free Composite Body Valve
Lead-FreePotable WaterNSF/ANSI 372

The ASCO 212 Series uses a composite (non-metallic) body to meet lead-free requirements for potable water applications under the Safe Drinking Water Act and ANSI/NSF 372 certification. Standard brass valves — even "lead-free brass" variants — may not meet all state or municipal requirements for drinking water contact. The 212 series eliminates the concern entirely with a fully compliant composite body.

Available with press-fit and expansion fitting connections in addition to standard NPT threading, making it a strong fit for retrofit plumbing applications where flame-free installation is required or preferred.

Choose the 212 when: Your application involves potable water and lead-free compliance is required by code, spec, or owner preference, or you need flameless press/expansion fitting connections for retrofit work.

Lead-Free Composite
Potable Water
NSF/ANSI 372, SDWA
NPT, Press, Expansion
N/O or N/C
Municipal / Commercial Water
Potable water or lead-free required? 212 Series is your answer.Request a Quote →

ASCO Series Comparison at a Glance

Use this table to quickly identify which ASCO series fits your application. When your application spans multiple columns, the more specific series wins.

ASCO Solenoid Valve Series Comparison
Feature82108214822382628220/8263212
Primary MediaAir/Gas/Water/OilFuel Gas OnlyAir/Gas/WaterAir/Gas/Water/OilSteam/Hot WaterPotable Water
Pipe Size Range3/8"–2-1/2"3/8"–3"1/4"–1"1/8"–3/8"1/8"–2-1/2"Varies
Max Pressure150–300 psiStandardUp to 1,500 psi180 psiSteam ratedStandard
Direct ActingPilot operated—Piston✓ Yes✓ Yes (8263)—
Zero Min Pressure✗ 5 psi min✓✗✓✓✓
Steam Service✗ Not rated✗✗✗✓ Rated✗
UL/FM Gas ApprovalGeneral only✓ Safety Shutoff————
Lead-Free CompliantOption only————✓ NSF/ANSI 372
Explosion Proof Option✓ Types 7/9✓✓✓✓—
Body MaterialBrass or SSBrassBrass or SSBrass or SSBrass or SSComposite

ASCO Application Matching Guide

Match your real-world scenario to the right ASCO series. If your application doesn't fit neatly into one scenario, call us — we'll work through it with you.

General HVAC or Industrial Air/Water Control

Standard shutoff or on/off control for water, air, or inert gas in typical industrial or HVAC pressure ranges.

→ ASCO 8210 Series

Gas Burner Fuel Train — Safety Shutoff Required

NFPA 85 or insurance requirements call for listed safety shutoff valves on the fuel train. General service valves don't qualify.

→ ASCO 8214 Series

Steam Supply or Hot Water Control

High temperature media breaks down standard valve seals fast. Standard 8210 is not rated for steam — this is a common and expensive mistake.

→ ASCO 8220 / 8263 Series

High Pressure System — Above 300 psi

Hydraulic circuits, high-pressure compressed air, or high-pressure gas systems that exceed standard solenoid valve ratings.

→ ASCO 8223 Series

Very Small Pipe or Zero Pressure Differential

1/8"–3/8" pipe sizes, vacuum service, or applications where minimum pressure differential for a pilot-operated valve can't be guaranteed.

→ ASCO 8262 Series

Potable Water — Lead-Free Required by Code

Municipal, commercial, or residential potable water applications where state or local code requires NSF/ANSI 372 lead-free certification.

→ ASCO 212 Series

Hazardous Location — Explosion Proof Required

Class I Division 1 or 2 locations where an explosion-proof or intrinsically safe solenoid enclosure is required by electrical code.

→ 8210 / 8223 Exp. Proof Options

Replacing an Existing ASCO Valve

Have a catalog number from the nameplate? That's all we need. If the tag is gone, pipe size + media + voltage gets us close enough to find a direct replacement fast.

→ Call (901) 458-2000

Not Sure Which Series You Need?

Tell us your pipe size, media, pressure, and voltage — we'll identify the right ASCO part number and get it shipped same day if it's in stock.

Request a Quote(901) 458-2000

Frequently Asked Questions

What information do I need to order an ASCO solenoid valve?
Five things: pipe size (NPT), the media going through it, operating pressure, supply voltage, and whether you need normally open or normally closed operation. If you have an existing catalog number from the valve's nameplate, that's even better — we can pull the exact replacement or cross-reference directly.
Can I use an ASCO 8210 for steam service?
No — and this is one of the most common mistakes we see. Standard 8210 valves use NBR seals that are not rated for steam temperatures. Steam service requires the 8220 series (larger sizes) or the 8263 series (1/8"–3/8" sizes), both of which are built with high-temperature seals and materials specifically for steam and hot water applications.
What is the difference between normally open and normally closed?
Normally closed (N/C) is shut when de-energized — apply power to open, remove power to close. Normally open (N/O) is open when de-energized — apply power to close. For safety shutoff applications, normally closed is almost always correct. If you're unsure which you need, think about what should happen if power fails — if flow should stop, use N/C.
Do I need the 8214 series for gas, or will a standard 8210 work?
It depends on the application. For general gas control where safety shutoff valve listings aren't required, a standard 8210 in the appropriate gas construction works fine. But for fuel gas on a commercial or industrial burner fuel train — where NFPA 85, NFPA 54, or insurance requirements mandate UL/FM-listed safety shutoff valves — you need the 8214 series. When in doubt on a burner application, always spec the 8214.
What does "pilot operated" vs "direct acting" mean for my application?
A pilot-operated valve (like the 8210) uses line pressure to help open or close — it requires a minimum pressure differential (typically 5 psi) across the valve to function. A direct-acting valve (like the 8262) is actuated entirely by the solenoid coil and works at zero pressure differential, including vacuum service. If you're not certain your system will always have adequate pressure differential, use a direct-acting valve.
Memphis Control Center stocks ASCO solenoid valves?
Yes — we're an authorized ASCO distributor with common series and configurations in stock. We ship same-day on in-stock orders placed by 2 PM CT. For less common configurations, lead times are typically short. Call us at (901) 458-2000 or use the quote form with your specs and we'll confirm availability and turn it around fast.