Temporary Conical and Basket Strainers
Temporary conical (cone) and basket strainers (conical with flat end) are mostly used to remove debris and to offer protection of equipment during the start-up period. When building a new pipeline there is always a chance that items, such as weld beads and slag, did not get completely cleaned out of the pipeline. A weld bead (ball) moving down a gas pipeline at a high velocity would act like a bullet being shot from a gun. Temporary strainers act like a safety net in the design. Over the past 40 years that our engineers have been involved with designing or selling this type of equipment, they have heard of chipping hammers, hard hats, and lunch boxes being left in the lines.
One particle of scale, weld bead, dirt, or other entrainments can cause sever damage to expensive equipment. To prevent damage, temporary strainers are used and must be designed of durable corrosion-resistant materials.
Extreme loading that can be introduced on the surface of the strainer causes the open area ratio to decrease as the debris builds up. Therefore, it is necessary to add a support cage structure to insure a higher safety factor. This support cage is highly recommended in reverse flow, high-pressure applications.
The temporary strainer is usually installed in a spool piece equal or longer in length with the gasket end of the temporary strainer located between a matching pair of flanges. By removing the bolts on both ends of the spool piece, the assembly can easily be removed from the pipeline for cleaning.
On Page 2 is a BSL-RTJ conical basket strainer that is now being offered in our product mix for new gas pipeline construction. This is mostly for applications where RTJ flanged connections are being used.
Flat face designs in the 300# and 600# construction are also available as shown on Page 3. As we see higher-pressure pipelines and LNG systems being built, there will be a growing demand for temporary strainers being used with RTJ flanges. The RTJ metal to metal sealing gasket is used in the ANSI connection, primarily in the 600#, 900#, 1500#, 5000#, and 10,000# rated flanges.