Hayward Standpipe and Underdrain Assembly | VLX4001A Fire Pit Proper filtration is essential for

Proper filtration is essential for water clarity and chemical efficiency

With the manufacturer SKU 9-100-1204

80ft Cable Included – Allows flexible installation for various pool layouts

and advanced electronic or integrated control systems

Napoleon built-in linear fireplaces requiring PSB74SS barriers

Hayward Standpipe and Underdrain Assembly | VLX4001A Fire Pit Proper filtration is essential forWhat This Part Is Used For The Hayward VLX4001A is a standpipe and underdrain assembly used inside compatible Hayward VL Series sand filters. It manages internal water distribution through the sand bed and supports proper filtration and backwashing. This assembly lives inside the filter tank under the multiport valve connection. Why This Part Matters If the internal underdrain components are cracked or out of position, the filter can bypass sand and