Air-controlled, direct-acting relief valve - pilot capacity
Two-port, pilot-stage, air-controlled, direct-acting relief cartridges are normally closed pressure regulating valves. When the pressure at port 1 (inlet) is sufficient to overcome the force due to the air signal, a flow path is opened from port 1 to port 2 (tank). These cartridges are designed for pilot flow applications and utilize Sun's T-8A cavity so they can be used in conjunction with Sun's pilot-operated, main-stage valves.
- Utilizes the Sun T-8A 2-port cavity making it the ideal choice to use in conjunction with Sun's main stage pilot or vent-to-operate cartridges. Separate pilot lines are eliminated and only one cavity needs to be machined to accommodate both the control and primary function. Note: All 2-position, 2-way pilot stage control cartridges utilize the same cavity and are physically interchangeable. Functionality is the only consideration.
- Note: The main stage valve should first be installed to the correct torque value followed by the T-8A pilot control section into the main stage valve to its required torque value.
- Different pilot control port options are available. See Option Selection for details.
- Ports 1 and 2 may be pressured to 5000 psi (350 bar).
- Hardened poppet and seat provide consistent operation, low leakage rates and superior wear characteristics.
- Two different oil-to-air pilot ratios are available; 50:1 and 75:1. See Option Selection.
- Maximum pilot control port pressure is 150 psi (10 bar).
- Backpressure at port 2 increases the relief setting by a .43 multiplier.
- 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.
|Capacity||2.5 gpm10 L/min.|
|Maximum Operating Pressure||5000 psi350 bar|
|Maximum Valve Leakage at 110 SUS (24 cSt)||15 drops/min.1 cc/min.|
|Maximum Pilot Pressure||150 psi10,5 bar|
|Pilot Control Port||See Control OptionsSee Control Options|
|Valve Installation Torque||20 - 25 lbf ft27 - 33 Nm|
|Seal kit - Cartridge||Buna: 990608007|
|Seal kit - Cartridge||EPDM: 990608014|
|Seal kit - Cartridge||Polyurethane: 990008002|
|Seal kit - Cartridge||Viton: 990608006|
There are exactly 250 Sun drops in a cubic inch or 15 in a cc.
Maybe not. We build in a good amount of overlap in the kick-down reliefs to prevent false tripping. This means they are not as fast as our standard pilot-operated reliefs. A direct-acting relief valve set just above the kick-down relief valve would be good insurance.
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.
One graphic example is on a portable grain auger for silos. When the farmer gets caught in the auger the kick-down relief trips and allows him to escape.
Pressure setting tolerances are listed in our Performance Data page. A link to this page can also be found in the Additional Resources tab of the applicable product page.
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- Pressure Equipment Directive 2014/68/EU