Hayward
Hayward SX311MAS Lateral Holder Assembly (Elbow Included)
Hayward SX311MAS Lateral Holder Assembly (Elbow Included)
Hayward SX311MAS Lateral Holder Assembly with Bottom Vertical Pipe and Bottom Elbow
The Hayward SX311MAS Lateral Holder Assembly is a genuine OEM internal filter replacement part for select Hayward ProSeries high-rate sand filters. This assembly is designed to replace the lower internal underdrain section that supports proper water movement through the sand bed during filtration and backwashing.
Hayward identifies the SX311MAS as the lateral holder assembly, bottom vertical pipe, and bottom elbow assembly for the Hayward ProSeries S311SX. If your original internal assembly is cracked, worn, damaged, or no longer aligning correctly, this OEM replacement helps restore proper internal fit and function.
This part is intended for the Hayward ProSeries S311SX. Please confirm your filter model number from the label on the tank before ordering. If you have a different model, the correct internal assembly may be different.
Product Features
- Genuine Hayward replacement part
- Manufacturer part number: SX311MAS
- Designed for Hayward ProSeries S311SX sand filters
- Includes the lateral holder assembly, bottom vertical pipe, and bottom elbow assembly
- Helps maintain proper internal water flow through the filter during filtration and backwash cycles
- Direct OEM replacement for a worn, cracked, or damaged original assembly
- Engineered for in-ground pool filter applications
Compatible Filter Model
| Brand | Series | Compatible Model |
|---|---|---|
| Hayward | ProSeries High-Rate Sand Filter | S311SX |
What This Part Does
The internal lateral holder assembly is a critical part of the filter underdrain system. It supports the lower internal structure that directs water through the sand media and back into the pool system. When this assembly is damaged, worn, or mismatched, it can lead to internal fitment problems, poor circulation through the media bed, or service issues during reassembly.
Replacing a damaged OEM assembly with the correct Hayward part helps maintain proper alignment and restore the intended internal configuration of the filter.
When Should the SX311MAS Be Replaced?
- The original lower assembly is cracked, broken, or warped
- The bottom elbow or vertical pipe is damaged
- The internal assembly no longer aligns or seats correctly
- You are rebuilding the lower internal section of an S311SX sand filter
- The original assembly has become brittle from age, chemical exposure, or service wear
This listing is for the SX311MAS assembly only. The ribbed laterals are sold separately. If your laterals are damaged as well, you may need additional replacement parts to complete the repair.
Frequently Asked Questions
Does the Hayward SX311MAS include the elbow?
Yes. Hayward identifies the SX311MAS as the lateral holder assembly with the bottom vertical pipe and bottom elbow assembly.
Does this include the laterals?
No. The ribbed laterals are listed separately in the Hayward parts diagram. If those are cracked or worn, they must be purchased separately.
Will this fit every Hayward ProSeries sand filter?
No. The SX311MAS is intended for the S311SX. Other ProSeries models use different internal assemblies, so it is important to verify the exact filter model before ordering.
Send Aqua Terra Backyard your filter model number and a photo of the label on the tank. We can help confirm whether the Hayward SX311MAS is the correct internal assembly for your sand filter.
