Straining is a process regularly applied to liquids and gasses, and can be compared with the sieving process sometimes applied to solids. In the latter case, for example, a cook may choose to pass apparently smooth flour or icing sugar through a sieve in order to remove any unseen tiny lumps that might otherwise spoil the texture of dough or fondant. When applied to liquids, the process of straining to remove lumps from a liquid will often take place in a pipeline for which the help of either a basket or Y strainer is required.
The two devices are intended to perform the same basic function, which is to remove particulate matter from a flowing liquid. However, their differing designs serve to determine the type of application for which each of them is likely to be best suited. Both devices will need to be physically cleaned from time to time, and both how this must be done and how often it will be necessary are factors to be considered when deciding whether it will be more efficient to use a Y strainer or to install one of the basket-shaped types.
Depending upon the precise requirements of a given application, each of these devices may display both advantages and disadvantages and these must be carefully considered before deciding on which may prove to be the most suitable solution. In this case, the proposed orientation of the device when installed could be a game-changer. If, for example, the device is to be installed in a vertical section of the pipeline, the Y strainer become the only possible choice as, unlike the basket design which only functions if installed horizontally, it is designed to function in both planes.
Orientation is just one of the factors that can influence the choice of device, however. In practice, one of the more critical of these is the pressure to which it will be subjected during the proposed operation. In this respect, there is no real contest. The basket models are simply no match for a Y Strainer when it comes to handling high pressures. Interestingly, they were first introduced as a means to free steam, air, and inert gasses from the pieces of pipe scale and worn gasket that frequently find their way into the process flow in ageing pipelines, but were found to be equally valuable in flowing liquids.
Although they are more compact and cheaper than the alternative basket-design, the Y strainer does have one significant limitation. It is best suited to situations where the concentration of particulate matter is relatively low or where contamination is not normally expected.