Pentair Genuine OEM Lateral for 18 in and 20 in Filters, 1/4 Turn, After 10/04

This is the genuine Pentair 150084 lateral, the quarter turn style used in 18 inch and 20 inch sand filter tanks manufactured after 10/04. It measures 5.25 inches long with a 1.25 inch diameter at the connecting end.

What a lateral does

Laterals are the slotted arms that spread out from the bottom of the standpipe inside a sand filter. Filtered water passes through their slots on the way to the return line while the sand stays behind. The slots are narrow enough to hold sand back, which also makes them the first thing to crack when a filter is run dry, when the tank is moved with sand in it, or simply with age. Once one splits, sand goes straight into the pool and no amount of backwashing will stop it.

Fitment

Beyond the 18 and 20 inch tanks, this lateral has been used with the Meteor Filter System 18 and 20 inch tanks, the Sand Dollar SD35 and SD40, the Cristal-Flo II filter systems in 16 and 19 inch tanks, the Eclipse and Meteor top mount filter, and some Tagelus models. Note that the compatible list reaches past the 18 and 20 inch sizes named in the part description, so compare the old lateral against the measurements above, and check with Pentair if your filter is not on the list.

While the filter is open

Laterals are only reachable with the sand out of the tank, so inspect all of them at the same time. A set that has one broken arm usually has others that are close to failing, and the labor of emptying the tank is the expensive part of the job.