![\"41.png\"](\"https:\/\/ecdn6-nc.globalso.com\/upload\/p\/4422\/image_other\/2026-09\/41.png\")
<\/p>\nGuangzhou, Guangdong Province, China-October 27, 2026<\/p>\n
I am Victor. I own a 6,000 m² factory in China and am a renowned relief valve expert.<\/p>\n
Pressure Regulation and Overflow Function<\/p>\n
In a hydraulic system powered by a fixed-displacement pump, a certain pressure level is required to meet the demands of the working load. The system needs “pressure regulation”—that is, determining the maximum operating pressure of the Hydraulic Pump. On the other hand, when the actuator does not require that much flow, the fixed-displacement pump still supplies a constant flow. The only way to handle the excess flow is through the relief valve, which overflows the surplus oil back to the tank. Without this, the excess flow would cause system pressure to rise to a dangerously high level. Therefore, in a fixed-displacement pump hydraulic power system, the relief valve serves the functions of “pressure regulation,” “pressure limiting,” and “overflow,” as shown in Figure 3-1(a).<\/p>\n
Safety Protection Function<\/p>\n
In a hydraulic system where a variable-displacement pump serves as the power source, the pump flow generally adjusts automatically with the load, so there is usually little excess flow. Its working pressure is determined by the load. The relief valve only opens to overflow when pressure exceeds a pre-set value, preventing further pressure rise, protecting the system from overload, and serving a safety function, as shown in Figure 3-1(b).<\/p>\n
Pump Pressure Build-up or Unloading on Demand<\/p>\n
In this type of hydraulic system, a solenoid-operated relief valve is used, as shown in Figure 3-1(c). When the solenoid is energized, the external control port of the relief valve is connected to the tank, enabling the pump to unload.<\/p>\n
Remote Pressure Control and Two-Stage Pressure Control<\/p>\n
In Figure 3-1(d), a remote pressure control valve is installed at a convenient operating location. The external control port X (remote control port) of the pilot-type Main Relief Valve is connected to the remote pressure control valve (a relief valve with a lower pressure setting). That is, the upper chamber of the Main Relief Valve spool is connected to external control port X. When the solenoid valve is de-energized, as soon as the adjusted pressure reaches the setting of the remote pressure control valve, the main valve spool lifts to overflow (its pilot valve no longer performs pressure regulation)—thus achieving remote pressure control. When the solenoid valve is energized and the left position is active, pressure is regulated by the Main Relief Valve. When the solenoid valve is energized and the right position is active, pressure is regulated by the remote pressure control valve. This gives the hydraulic system two working pressures, known as two-stage pressure control.<\/p>\n
<\/p>\n
Figure 3-1: Applications of Relief Valves<\/p>\n
Multi-Stage Pressure Control<\/p>\n
As shown in Figure 4-60, the A1 and B1 ports of a normally closed pilot solenoid valve are connected to a two-stage and a three-stage direct-acting relief valve (pressure regulating valve) respectively. If the main valve, two-stage, and three-stage direct-acting relief valves are each adjusted to different pressures, three-stage pressure control can be achieved. For example, if P1 = 20 MPa, P2 = 10 MPa, and P3 = 5 MPa, then when both solenoids are de-energized, system pressure is 20 MPa; when solenoid 1DT is energized, system pressure is 10 MPa; when solenoid 2DT is energized, system pressure is 5 MPa. If a normally open pilot solenoid valve is used, the system unloads when the solenoid is de-energized. Multi-stage pressure control requires the use of an externally controlled relief valve.<\/p>\n
![\"42.png\"](\"https:\/\/ecdn6-nc.globalso.com\/upload\/p\/4422\/image_other\/2026-09\/42.png\")
<\/p>\n
Figure 3-2: Multi-Stage (Three-Stage) Pressure Control with Solenoid Relief Valve<\/p>\n
As shown in Figure 3-3, the control oil port X of main pilot-operated relief valve 1 is connected to a three-position four-way solenoid valve 4. Ports A and B of the solenoid valve are each connected to a pressure regulating valve (direct-acting relief valve) 2 and 3 respectively. When the three relief valves 1, 2, and 3 are adjusted to different pressures P1, P2, and P3 respectively, three-stage pressure regulation of the system can be achieved. Note that P2 and P3 must be lower than P1; otherwise, they will not take effect.<\/p>\n
![\"43.png\"](\"https:\/\/ecdn6-nc.globalso.com\/upload\/p\/4422\/image_other\/2026-09\/43.png\")
<\/p>\n
Figure 3-3: Three-Stage Pressure Regulation Circuit<\/p>\n
1-3 — Relief Valves; 4 — Three-position Four-way Solenoid Valve<\/p>\n
Contact me via WhatsApp: +86 15356071276<\/p>\n
About US<\/p>\n
Guangzhou FuTeBang Machinery Equipment Co., Ltd. has been deeply engaged in the excavator parts industry for over 15 years, integrating production, R&D, and sales to provide a full range of high-quality products for the market. Its core product lines include various relief valves, hydraulic spare parts, joystick valves, and foot pedal valves, which are precisely compatible with mainstream brand models such as Komatsu, Caterpillar, Hitachi, Sumitomo, Kato, Daewoo, and Hyundai.<\/p>\n
Media Contact<\/span> Guangzhou, Guangdong Province, China-October 27, 2026 I am Victor. I own a 6,000 m² factory in China and am a renowned relief valve expert. Pressure Regulation and Overflow Function In<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"_links":{"self":[{"href":"https:\/\/www.pennsylvania-magazine.com\/news\/wp-json\/wp\/v2\/posts\/620880"}],"collection":[{"href":"https:\/\/www.pennsylvania-magazine.com\/news\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.pennsylvania-magazine.com\/news\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.pennsylvania-magazine.com\/news\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.pennsylvania-magazine.com\/news\/wp-json\/wp\/v2\/comments?post=620880"}],"version-history":[{"count":0,"href":"https:\/\/www.pennsylvania-magazine.com\/news\/wp-json\/wp\/v2\/posts\/620880\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.pennsylvania-magazine.com\/news\/wp-json\/wp\/v2\/media?parent=620880"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.pennsylvania-magazine.com\/news\/wp-json\/wp\/v2\/categories?post=620880"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.pennsylvania-magazine.com\/news\/wp-json\/wp\/v2\/tags?post=620880"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
Company Name:<\/strong> Guangzhou FuTeBang Machinery Equipment Co., Ltd.<\/a>
Contact Person:<\/strong> Media Relations
Email:<\/strong> Send Email<\/a>
Country:<\/strong> China
Website:<\/strong> https:\/\/www.chinaftb.com\/<\/a><\/p>\n<\/p>\n","protected":false},"excerpt":{"rendered":"