ASCO Red Hat Solenoid Buying Guide

Solenoid valves are critical components in fluid automation, serving as the interface between electronic control systems and mechanical fluid flow. Within the ASCO Red Hat product line, a variety of configurations exist to meet specific application requirements for pressure, flow, and media compatibility. This guide provides a detailed technical overview of these valves to assist in selecting the correct model for a given operational environment.

• Core Principles of Solenoid Operation
• 8210 Series: High-Flow General Service
• 8262 & 8263 Series: Direct Acting Control
• 8320 Series: 3-Way Control
• Specialized Valves: Fuel Gas & Actuation

A solenoid valve operates using an electromagnetic coil to actuate a plunger that controls the flow of a fluid through a valve body. The ASCO Red Hat series includes several types of internal mechanisms that determine how the valve responds to electrical signals and fluid pressure.

Direct Acting vs. Pilot Operated

Direct-acting valves, such as the 8262H232, use the solenoid’s magnetic force to move the valve seal directly. These are capable of operating from 0 psi up to their maximum rated pressure.

In contrast, pilot-operated valves like the 8210G009 use the pressure of the fluid in the line to assist the opening and closing of a diaphragm. These valves require a minimum operating pressure differential (typically 5 psi) to function correctly but can handle significantly higher flow rates for their size.

The 8210 series is a primary choice for high-flow applications involving air, water, and light oils. These are 2-way, normally closed or normally open valves that utilize a pilot-operated diaphragm.

8210 Series Specifications

The 8210G094 is a specialized "zero differential" pilot valve, allowing it to provide high flow even when the pressure differential is near zero, bridging the gap between direct-acting and standard pilot designs.

When a system requires low flow, vacuum operation, or zero-pressure performance, direct-acting valves are the preferred selection. The 8262 series is compact and versatile, while the 8263 series is often used for high-temperature applications.

8262 and 8263 Series Specifications

For cryogenic applications involving liquid nitrogen or liquid oxygen, models like the 8262H114LT are built with specific stainless steel internals and Teflon (PTFE) seals to handle extreme thermal stress without leakage or sticking.

3-way valves have three ports and two orifices, allowing them to pressurized a line and then exhaust that pressure, making them ideal for piloting larger valves or actuating single-acting pneumatic cylinders.

3-Way Valve Comparison

The 8320R172 100-240 features a "Next Gen" electronic coil. These coils utilize an internal circuit to allow the valve to operate on a wide range of input voltages (100V to 240V AC/DC) while maintaining low power consumption and silent operation.

Some environments require specialized materials or enclosure ratings due to the nature of the media or the surrounding atmosphere.

Fuel Gas Service (8215 Series)

The 8215 series is specifically designed for the control of fuel gases. These valves often use aluminum bodies to reduce weight and are designed for large-capacity gas trains.

• 8215G080-24/DC: A 2" NPT aluminum valve with a high $C_v$ of 60, suitable for high-volume gas flow.
• 8215A040CSA: A 3" NPT version designed for large industrial burner systems.

Spool Valves for Actuation (8551 Series)

The 8551 series consists of spool valves primarily used for the control of pneumatic actuators.

• WT8551A001MS: This 3/4-way configurable valve can be mounted directly to an actuator or used with remote piping.
• EF8551A017MS: An explosion-proof version of the 8551, suitable for oil and gas or chemical processing sites.

When evaluating a Red Hat valve, several technical factors must be calculated to ensure system reliability.

Flow Coefficient 

• The 8215 Series is engineered specifically for controlling fuel gases, combining high flow capacity with lightweight construction. Featuring durable aluminum bodies, these valves help reduce overall system weight while maintaining reliable performance in demanding gas applications.

8215G080-24/DC: A 2" NPT aluminum valve with a high flow coefficient ($C_v$) of 60, making it ideal for high-volume gas flow applications.
 8215A040CSA: A 3" NPT valve designed for large-scale industrial burner systems requiring robust, high-capacity gas control.

Seal Material and Temperature Range

The choice of elastomer determines the chemical resistance and temperature limits of the valve.

• NBR (Buna-N): Used for air and water up to $180^{\circ}F$.
• FKM (Viton): Used for high-temperature liquids and many chemicals.
• EPDM: Ideal for hot water and steam, but incompatible with petroleum-based oils.
• PTFE (Teflon): Required for steam and cryogenic fluids, as seen in the 8220G410.

Electrical and Enclosure Ratings

Electrical requirements must match the control system. Red Hat valves are identified by prefixes that indicate their enclosure rating:

• Standard: No prefix, typically Type 1 general-purpose enclosure.
• SC: DIN connector or molded epoxy coil for watertight applications.
• EF: Explosion-proof enclosure (Type 7/9).

WT: Watertight and corrosion-resistant (Type 4/4X).

Proper installation is critical for the longevity of a solenoid valve. Most Red Hat valves should be mounted with the solenoid vertical and upright to prevent debris from settling in the core tube.

Maintenance and Troubleshooting

If a valve fails to operate, the first step is to verify the supply voltage at the coil. If the coil is functional but the valve does not actuate, the internal diaphragm or pilot orifice may be clogged.

• Coil Replacement: The solenoid coil can be replaced without removing the valve body from the plumbing.
• Rebuild Kits: ASCO provides specific rebuild kits for each model number. These kits typically contain a new diaphragm, springs, and seals. For example, the 8210G054 uses a 1" diaphragm kit that can be installed by removing the four bolts on the valve bonnet.

By following these technical guidelines and selecting the specific series—whether it be the high-flow 8210G009 or the compact 8262H232—users can ensure their fluid control systems operate within their design specifications.

Product Compliance and Suitability

The product statements contained in this guide are intended for general informational purposes only. Such product statements do not constitute a product recommendation or representation as to the appropriateness, accuracy, completeness, correctness, or currentness of the information provided. Information provided in this guide does not replace the use by you of any manufacturer instructions, technical product manual, or other professional resource or adviser available to you. Always read, understand, and follow all manufacturer instructions.