Pressure and flow considerations for Hydraulic Tanks and Reservoirs

In the realm of hydraulics reservoirs, it is frequently considered to be "just an empty tank." In fact, it's actually the lungs and organs for your entire hydraulic system. It does more than just hold oil; it also handles heat, collects and settles contaminants, and, most importantly, controls the flow and pressure that prevent your pumps from self-destructing.

If you're planning or managing a system, knowing how flow and pressure are interconnected within the tank is the distinction between a flawless operation and a disastrous failure.

1. The Suction Side: Preventing Cavitation

The most important flow consideration is the route between the reservoir and the pump's intake. This is the point where positive pressure (vacuum) becomes a big danger.

• Flow Velocity To avoid turbulence and pressure drops in suction lines, flow should usually be maintained between 2 and 4 feet per second.

• The dangers of Cavitation: If the fluid is not able to flow through the pump in a timely manner, and the pressure falls below the vapor pressure of the fluid. tiny bubbles begin to form, and they explode violently, creating pits on the surface ofthe metal and damaging pumps.

• Solutions: Always ensure the suction line is as narrow and straight as you can.

2. Return Line Dynamics: Managing Turbulence

When oil is returned into the tank typically returns at high velocity and at higher temperatures. How you manage this flow will determine what you can do to improve the "health" for the petroleum.

• Differers: Don't let the return line just "dump" liquid into the tank. This can cause the possibility of aeration (bubbles). Utilize the diffuser to slow this flow as well as spread it.

• The Baffle Plate: A well-designed reservoir utilizes a baffle plate that separates both sides from suction. This causes the oil to follow a long route and allows it to cool, and allows for air bubbles to ascend up to the surface before being returned to the pump.

3. Pressurized vs. Vented Reservoirs

Depending on the conditions and your application, you will need to decide on how the tank "breathes."

4. Fluid Level and Effective Volume

Flow isn't only about speed; it's also about the duration of residence.

The most common standard suggests that the tank must be able to hold three to five times the output of the pump each minute. If you own an 10- GPM pump, you should have a tank that is 30-50 gallons.

• Low flow/high volume allows for improved cooling and also de-aeration.

• Low Volume/High Flow: Leads to "foaming" and overheating as the oil isn't in the tank for long enough to cool down.

5. The Role of the Breather

When the rods of the cylinder extend as they retract amount of fluid within the tank fluctuates and decreases. It is a sign that the tank is continuously "inhaling" and "exhaling" air.

• Pressure Spikes. If a breather has become blocked, the pump drawing oil could cause a vacuum that collapses the tank or even starves the pump.

• Contamination. In the event that airflow isn't controlled by at least 10 microns, the reservoir will become an entry point for dust, which results in the appearance of a powder when combined with hydraulic oils.