DO2 Valve Data - AAA Products International

AAA Products International Inc.
7114 Harry Hines Blvd.
Dallas, Texas 75235
214-357-3851

Data for DO2

The DO2 is a 1/4" NPTF side ported, 2 position, spring return, differential pilot operated valve. The internal spool is shifted by depressing the button bleeder installed in the 1/8" NPTF pilot port in the end cap of the valve. Once the button bleeder is depressed and the internal pressure is vented, the spring shifts the spool. When the internal pressure is greater than 80 psi, the spool will be fully shifted, compressing the spring. There is no consistent correlation between the amount of internal pressure and the amount of spool travel. The buttons can be remotely located. The response time of the valve shifting is dependent upon the distance from the button to the valve as well as the hose diameter used (smaller diameters allow faster response times).

Details

Pressure: 50 to 250 psi on the main body of the valve.
Vacuum: Button bleeder valves cannot be used for vacuum service.
Temperature: -20°F to 250°F. Caution: If it is possible that the ambient temperature may fall below freezing, the medium must be moisture free to prevent internal damage or unpredictable behavior.
Mounting: The spool is friction positioned so the valve must be mounted with the spool in a horizontal orientation.
O-Rings: Viton.
Materials: Black anodized 6061-T6 aluminum body, hard anodized aluminum spool, A380 aluminum end caps, composite gaskets, steel fasteners. The button bleeder is half hard brass with a steel button.
Flow: 73.9 SCFM, 1.6 Cv
Repair Kit: ERKV-3.
3-Way: While this valve is basically 4-way, it can be used for 3-way service by plugging the unused port 2 or 4, port 1 must remain pressurized to create the differential pressure required to shift the spool.
Fluid Media: Soft seal models are made for air, vacuum, and gases compatible with component materials. They should not be used with liquids.
Weight: 1.30 lbs.

General - Differential Pilot Accessories

The following accessories are available for differential valves or general purpose use.

Image	Part No.	Description
	BB-1S	Steel bleed button, replacement button same as original equipment on all AAA differential pilot valves. Threaded 1/8" NPT. Hex size is 1/2". Extends approximately 3/4" when installed with 0.08" travel. Requires 4.5 lbs. operating force on 100 PSI line. Drawing
	BB-1SSL	Same as BB-1S except with larger 5/8" diameter stainless steel head and spring for heavy duty applications. Threaded 1/8" NPT. Hex size is 1/2". Extends approximately 3/4" when installed with 0.08" travel. Requires 5 lbs. operating force on 100 PSI line. Drawing
	BB-1P	Same as BB-1S, with hard black plastic palm button 1-3/8" diameter. For use as manual control or panic button. Threaded 1/8" NPT. Hex size is 1/2". Extends approximately 1-1/2" when installed with 0.08" travel. Requires 4.5 lbs. operating force on 100 PSI line. Drawing
	TB-1/8	A convenient means of mounting a bleed button remotely. Body is 3/4" square x 1-1/8" long. Universal mounting with 1/8" NPTF ports on two sides. Mounts with two No. 10 or 3/16" screws. Drawing

General - Differential Pilot Operation

Differential Pilot models are special types in which full line pressure is maintained on both ends of the main spool. To shift the spool, one or the other bleed buttons on the end caps must be momentarily pressed. This vents pressure from one end, permitting pressure on the other end to shift the spool.
A minimum of 25 psi is required for reliable shifting of non-spring models. Minimum pressure for spring offset and 3 position models is 50 psi. They will not operate correctly on compressed air lines of less than 25 psi. They are not suitable for liquids. By careful design they can be built in a 3 position, spring centered configuration.
The bleed buttons can be removed from the valve body and mounted on 1/4" hose or tube extensions for shifting the valve from a few feet away. Any other 2-way normally closed (N.C.) valve, manual, cam or solenoid valve can be substituted for either or both bleed buttons.

DIFFERENTIAL OPERATION

General - Installation & Maintenance

Valves should be installed with reasonable accessibility for service. Exercise care in keeping tubing lengths to a minimum. Plumbing should be free of contamination. Pipe joint compound should be used sparingly applied only to the thread, never the valve body. Over tightening of pipe threads can fracture the joint causing leaks or failure. Protect the valve from exposure to extreme temperatures, dirt and moisture to maximize life.
Bulletin A-113: Operating & Maintenance Instructions.
Installation: Valve Fitting Installation.

WARNING:These products can expose you to chemicals which is(are) known to the State of California to cause cancer or reproductive harm. For more information, go to www.P65Warnings.ca.gov. Contact us for specific chemicals or materials used in a product.

General - Lubrication, Standard

All valves are pre-lubricated at the factory using Magnalube-G Teflon based all purpose grease. Valves are suitable for, and perform best in a non-lube service. For long life, use an air line filter/lubricator installed no further than 10-ft. from the valve. The filter should be rated 25 pm or finer. Use a good grade of petroleum base lubricating oil no heavier than SAE 10W. DO NOT OVER-LUBRICATE. This could cause the spool to stick. CAUTION! Do not use questionable fluids in air line lubricators. Do not use petroleum oil with detergent additives. Detergents, volatile or aromatic fluids may swell rubber seals in valves and cylinders. Never use cooking or vegetable oil as a lubricant. When cleaning AAA valves after extended service, lubricate the valve spool with AAA high film strength grease, or, use O-ring grease which is usually available from supply houses which sell O-rings. Magnalube-G is included in all valve repair kits for proper valve maintenance. If an additional amount of Magnalube-G grease is required, a 0.75 ounce tube is available under part number VGK-3. Never use any kind of oil, cup grease, or automobile chassis lubricant.

The shelf life of Magnalube-G regularly lasts for 10+ year intervals in closed packaging due to the extremely long operating life of the Elastomer-PTFE gelling agent and premium parafiinic mineral base oil. If the valve is stored for over 2 years, then a small reapplication of grease is suggested.

Magnalube-G Technical Document
Magnalube-G MSDS Document

An alternative grease for low temperature application, refer to Dow-55 grease.

General - O-Ring Information

Unless otherwise specified, all 1/4" and 3/8" soft seal valves come standard with Viton O-rings and all 1/2", 3/4", 1", 1-1/2" and 2" soft seal valves come standard with Buna-N O-rings. If a different material is required, use the dash numbers following the basic valve numbering code. For example, model RY3G-2 will have Silicone O-rings installed for a low temperature application. On valves larger than 1" consult factory on availability of O-ring materials. Additional O-ring material information.

Dash No.	O-ring Description	Temperature Rating
-2	Silicone	-80°F to 400°F
-3	Viton for most aromatic gases	-20°F to 400°F, 600°F for short time
-7	Urethane, 70 Durometer	-65°F to 200°F
-9	Buna-N	-40°F to 250°F

We are constantly researching O-ring materials to evaluate performance and durability in the AAA valve product line. Above is a compilation of the most commonly requested O-ring materials and the associated dash number. If you have a particular application that requires an O-ring material that is not listed, please contact us. Since we utilize standard O-ring dimensions in our valves, we can respond to the most obscure O-ring material request.