SPRING 6E1299 - Caterpillar

The RAPTOR valve can be equipped with one of two trim sizes, 1000 or 2000 mm2. In order to determine what trim size is needed for a particular application, the following Valve Sizing Diagram (Figure 5-1) has been provided. In addition to the available trim sizes, the TecJet gas metering valve (product specification 36116) sizing limits also have been added to this diagram for reference.The RAPTOR Valve Sizing Diagram outlines the maximum flow capabilities for a given trim size across a variety of gases and valve pressure drops. To use the diagram, the maximum flow rate for a given application must be determined in either a metric mass flow rate (kg/hr) or an English volume flow rate (sfcm). This value is found on the X-axis of the diagram. Choose the appropriate gas type: natural gas, air or specialty gas. Then choose the appropriate flow rate units. The next step will be to find the valve pressure drop at maximum flow on the Y-axis of the diagram. Metric (kPa) and English (psid) units are provided. Take the flow rate value and the pressure drop value, and determine where they cross on the diagram. This is the maximum flow rate operating point. To choose a trim size, simply pick the closest curve to the right of the intersection point and read what trim size the curve represents. Both the 80% and 100% flow area curves are given in the diagram. This is to aid in determining how much flow margin above the required maximum flow rate is available for a given size. If 20% margin is required, use only 80% flow area curve for sizing, if 0% margin is required, use only the 100% curve, and so on. Interpolation can be done to find immediate margins if necessary.As an example, let's say the maximum flow requirement is 400 kg/hr natural gas with a valve pressure drop of 9 kPa. Using the diagram, the closest curve to the right of this intersection point is the RAPTOR 1000, 100% flow area. Furthermore, a closer look shows a flow margin of approximately 15%. In this case, the RAPTOR 1000 trim size would be appropriate.RAPTOR Valve Sizing Diagram
Figure 5-1. RAPTOR Valve Sizing Diagram