Questions and Answers for Little Giant CV-SE2 2 in. PVC Sewage Check Valve

A:  Flapper

A:  This is a swing check not a ball check. If you open the PDF of the specification sheet, found under the header "Info and Guides" on the Home Depot product listing page it, contains a cutaway illustration.

A:  This product features an overall length of 4.25 inches.

A:  I just went to the warehouse with a tape measure. I got roughly 9 and a half inches.

A:  Yes. Its written on top (and you can look down valve body internally and see that flapper hinge should be at top if vertical orientation)

A:  Yes it stated on the side, but if want to look inside the flapper should open as fluid leaves the pump and close when the pump is off. so arrow should point away from pump and in the direction of the sewage tanks

A:  This check valve should be mounted on the vertical to support the water column above. As this is a Little Giant brand accessory it is typically used in connection with one of there sewage pumps. The best practice is to mount it on the discharge above the pump. As sewage pumps move fluid and will not air, I typically drill a small hole in the pipe below the check valve (but still in the sewage receptor) It the sump is allowed to completely empty and then fills slowly you will get air trapped in the pump volute and the area below the check. When the pump comes on next the impeller will not be able to compress the air enough to open the check. The system will be air bound. Thus there will be no flow. By drilling the air relief hole the air can be pushed out and the fluid can reach the check valve and open it. Yes sewage will continue to flow out the weep hole but that will be in the receptor.

A:  It is a one way flow. There is an arrow indicator molded on the unit.

A:  Most valves that I have seen of this type have a cracking pressure (opening pressure) of 0.5 psi, however I cannot specifically find this spec listed anywhere online or in the specifications for this particular model.

A:  It is a swing valve with no spring, so "cracking " is practically zero. If installing horizontally, and low flow conditions, pay attention to orient the hinge on top.

A:  I am not completely sure what you mean by "cracking PSI" I can tell you this check valve is pressure rated to 150 PSI. However residential sewage systems should never get near that.

A:  normal when the sewage back flows

A:  I have heard this criticism of various check valves throughout my time in this industry. What is odd is that the a style of check valve that is noisy in one application may not be in another. It depends on the velocity of the discharge, the amount of water column above the valve, the the valves placement.. The noise is typically the result of the water above the valve forcing it closed. There are "soft seated " check valves. and spring style valves, but they have there own issues. Obviously I can not see you installation. However I can tell you that in the past I have know plumbers to add additional check valves, so that the one is not carrying the entire weight of the water column and this has helped. As to your second question,. counter clockwise will loosen the screws. If you have further questions please feel free to give me a call. Chris 978 651 3301