We encourage you to have EECO size your valve. This assures proper valve sizing for your specific application. To have EECO size your valve, please print fill out the form(s) (click here) and fax the completed form(s) to EECO. To access this information as a printable PDF file, click here (Adobe Acrobat Reader 5 or later required).

A major consideration for proper operation of a hydraulic elevator system is proper sizing of the control valve in that system. By valve sizing, we are only referring to the proper selection of the internal components of the valve, not to the physical size of the valve or the size of its ports.

If down contract speed (full down speed with rated load on the car) is the same as the up, then the size of the standard valve (either the UV-5AT or UV-7B) is determined by the size of the bypass piston only. Sizing of the bypass piston requires only static pressure and flow rate. Locating the intersection of static pressure and flow rate on the sizing charts provided in Figure 1 and Figure 3 (on pages 13 and 15) provides the size of the valve. If Down contract speed is different from the Up, please contact EECO.

If the valve is for an existing installation, then the static pressure can be read from a pressure gage installed in the jack (ram) gage port of the existing valve when the empty car is resting at the bottom landing. However, if the valve is for a new installation or static pressure can not be physically measured, then empty car weight (weight of everything above the platen plate plus 1/2 of the piston weight) and jack piston diameter are required. With this information on hand, you can then calculate the static pressure by dividing the empty car weight by the cross sectional area of the piston, or use Table 1A (click here) or 1B, (metric, click here), to obtain the static pressure.

If the flow rate is known, the valve can now be sized. However, if the flow rate is not known, the car speed and jack piston diameter are required. Table 2A (click here) or 2B, (metric, click here), can then be used to obtain the flow rate. The flow rate can also be calculated by multiplying the car speed by the displacement factor for the specified piston diameter provided in Table 3 (click here).

As mentioned before, down contract speed is down speed with full load on the car. Down speed with empty car is less than contract speed depending on the ratio of full-load to no-load pressures (approximately 25% less for a two to one pressure ratio). If constant down speed is required between no-load and full-load conditions, UV-5ATC or UV-7BC valves should be used. Again, statice pressure and flow rate are required to size the valve.

Size the Up (bypass) section of the UV-5ATC by using the sizing chart in Figure 1 (click here). Then size the Down section of the UV-5ATC by using the sizing chart in Figure 2 (click here).

Size the Up (bypass) section of the UV-7BC by using the sizing chart in Figure 3 (click here). Then size the Down section of the UV-7BC by using the sizing chart in Figure 4 (click here).

Sometimes changes in the system specification would make it necessary to modify the operating condition in the field. The change may require the size of an existing valve to be changed at the job. This means that the bypass, check and down pistons may have to be replaced. If the size of the valve is changed in the field, we recommend that you indicate the new valve size on top of the valve. This will prevent confusion when the valve is serviced in the future.

CLICK HERE for a printable version of this information and tables.