Assembly Build Process

Sun's Assembly Build Process allows you to configure a cartridge and manifold, or main stage and pilot stage cartridge, and build a digital assembly in three dimensional space. The resulting output of this process is the assembly product page, including configuration-specific images, symbols, product information and CAD files for download.

The Assembly Build Process can be accessed from either a cartridge or manifold product page. Only valid choices are allowed.

From a manifold page, you must first choose your cartridge function. Once you choose your function, click on the BUILD ASSEMBLY button below the WHERE TO BUY BUTTON. Once clicked, you will be presented with valid cartridges for your manifold. Select the cartridge of your choice and follow the instructions at the top of the page. If your particular combination has been generated before, the resulting assembly page will be available immediately. If not, you will be asked to enter your email address. Once the page is complete, an email will be sent to you including a link to the assembly product page.

From a cartridge product page, click on BUILD ASSEMBLY and you will be presented with a listing of compatible manifolds. In the case of main stage and pilot stage cartridges, you can either build a cartridge to cartridge assembly or a cartridge to manifold assembly. Once your choice has been made, follow the instructions at the top of the page. If your particular combination has been generated before, the resulting assembly page will be available immediately. If not, you will be asked to enter your email address. Once the page is complete, an email will be sent to you including a link to the assembly product page.

Please note that the Assembly Build Process is an automated process. It can be utilized at any time. Pages are generated typically within minutes but delays can occasionally be expected. In the event of a delay, a team at Sun will work to resolve the issue to ensure you receive your information as quickly as possible.

2-way, pilot-to-shift directional valve with drain to port 4 - normally closed

Capacity: .5 gpm2 L/min. | Cavity: T-21A

Expand All

Technical Features [ + ]

The normally-closed, direct-acting 2-way directional cartridge with external drain is a pilot unloading valve used to sense pressure in one circuit to switch or unload a valve in a different circuit. When pressure at port 1 exceeds the setting of the valve, the spool shifts to connect port 2 to port 3.

The pilot area (port 1) and the spring chamber drain (port 4) are positively sealed.
There is spool leakage between the work ports (ports 2 and 3)of less than 20 drops/min (1,4 cc/min).
The valve is designed to not modulate and is the equivalent of a hydraulic pressure switch.
Incorporates the Sun floating style construction to minimize the possibility of internal parts binding due to excessive installation torque and/or cavity/cartridge machining variations.

Technical Data [ + ]

Note: Data may vary by configuration. See CONFIGURATION section.

Cavity	T-21A
Series	1
Capacity	.5 gpm2 L/min.
Maximum Operating Pressure	5000 psi350 bar
Maximum Valve Leakage at Reseat	20 drops/min.20 drops/min.
Reseat	>85% of setting>85% of setting
Valve Hex Size	7/8 in.22,2 mm
Valve Installation Torque	30 - 35 lbf ft41 - 47 Nm
Adjustment Screw Internal Hex Size	5/32 in.4 mm
Locknut Hex Size	9/16 in.15 mm
Locknut Torque	80 - 90 lbf in.9 - 10 Nm
Model Weight	.30 lb0,15 kg
Seal kit - Cartridge	Buna: 990021007
Seal kit - Cartridge	Polyurethane: 990021002
Seal kit - Cartridge	Viton: 990021006

Performance Curves [ + ]

Performance Curve for DRAX: 2-way, pilot-to-shift directional valve with drain to port 4 - normally closed

FAQs [ + ]

How big is a drop of hydraulic oil?

There are exactly 250 Sun drops in a cubic inch or 15 in a cc.

Direct acting or pilot operated - what do I use?

Direct-acting valves are used to prevent over pressure, and pilot-operated valves are used to regulate pressure. If you are unsure, use a direct-acting valve. Sun's direct acting valves are very fast, dirt tolerant, stable, and robust. Sun's pilot-operated valves are moderately fast, they have a low pressure rise vs. flow curve, and they are easy to adjust.

What parts of the Sun cartridge valve are field serviceable?

Only external seals are serviceable. Sun offers replacement seal kits for all cartridge models. The applicable kit part number can be found in the product page's Technical Data table or by using our Cartridge Seal Kit search function located under Accessories. Please note: Converting the external seals from one material to another does not ensure fluid compatibility with that material due to the existence of internal seals within the cartridge.

I used a DP** in a circuit but it hangs. What happened?

DP**s and DR**s are from the reducer/reliever family and are very capable of modulating. They are not bistable.

Where would I use a DR__ instead of a DP__?

In many circuits the directional cartridge is set to shift at a low pressure no matter how high the pilot pressure goes. If you use a DP__ , the pilot flow increases to significant amounts. A DR__ however will only consume a small amount of flow. A DP__ is useful when you want to block or open the pilot flow to shift the valve.

Additional Resources [ + ]

Highlights

Technical Tips