Automatic Backwash Valve, Starway exploded view & spare parts

Automatic Backwash Valve, Starway — exploded view & spare parts

This page presents the full exploded-view diagram and numbered bill of materials for the Starway Automatic Backwash Valve in the D.50 connection size, factory reference 7038735. The Starway is a motorised 5-way valve, available in Ø 50 mm and Ø 63 mm, designed to automate pool filter control. The motorised Starway valve automates the backwashing of swimming pool sand filters, managing both the service/filtration phase and the backwashing phase. The valve is equipped with an electric actuator with a closing function that always returns it to the filter position in the event of a power cut. Use the diagram and parts list below to identify your failed or worn component, match it to its position number, and locate its SKU — most visitors find what they need within a few minutes.

Hoe u het genummerde schema kunt gebruiken om uw onderdeel te vinden

Every numbered call-out in the exploded-view diagram corresponds directly to a row in the parts table below: the position number printed beside a component in the drawing is the same number shown in the “Pos.” column of the list. The most reliable way to work through the diagram is to start by identifying the area or sub-assembly where your fault lies — for example, the motor cover, the sealing stack, or the body tee — then zoom in on that region of the drawing to read off the relevant position number, and finally look that number up in the table to find the SKU you need to order. Bear in mind that some hardware items — such as the M6 hex nuts at position 8 and the M6 blind nuts at position 11, or the washers at positions 7 and 16 — can appear in multiple locations on the same valve, so you may need to count how many are required before placing your order. Pay close attention to material and dimensional callouts in the descriptions: for instance, positions 5 and 14 are both Viton O-rings but carry entirely different cross-sections (56.75 × 3.53 mm and 37.7 × 3.53 mm respectively), so selecting by position number rather than by appearance alone is essential. Where a part description references both the D.50 and D.63 sizes — such as the engine closing cover at position 9 — verify your valve’s connection diameter before ordering. If a position in this BOM shows no SKU, the part is either supplied as a sub-component of a larger assembly or is not currently available as an individual line item; contact our team for guidance in those cases.

Main replaceable assemblies on the Starway Automatic Backwash Valve D.50

The valve body is built around the ABS tee printed valve body at position 1 (SKU 7039409) and the ABS tee joint at position 12 (SKU 7039413), which together form the main hydraulic housing through which pool water is directed between filtration and backwash modes. The piston seal assembly is a common service item: the PVC seal piston at position 13 (SKU 7039414) creates the moving seal that switches water flow, and it works in conjunction with two Viton O-rings — the larger 56.75 × 3.53 mm O-ring at position 5 (SKU 7039410) and the smaller 37.7 × 3.53 mm, 90 Shore A O-ring at position 14 (SKU 7039415). A third, much smaller Viton O-ring at position 15 (SKU 7039416, 6.07 × 1.78 mm) seals a secondary passage and should be inspected whenever the valve is opened for service. The axis is manufactured from AISI 316L stainless steel, with Viton seals throughout. The central tie rod at position 2 and the lower pin at position 3 form this stainless steel actuation spine, while the closure tie rods at position 6 clamp the entire assembly together. The motor end of the valve is enclosed by the engine closing cover at position 9 (SKU 7039412), which fits both the D.50 and D.63 variants. The electronic control board at position 17 (SKU 7039417) governs the motor sequence, and the worm screw at position 20 (SKU 7039419, 140 mm) transmits drive from the motor to the valve mechanism. The lower ABS cap at position 19 (SKU 7039418) closes the opposite end of the body, and the semi-finished top cap at position 4 seals the upper portion of the valve housing.

Choosing between variants and pack sizes

Several positions in this BOM reference both the D.50 and D.63 connection sizes in their descriptions — most notably the engine closing cover at position 9 and the electronic board at position 17. The Starway valve is available in D.50 mm (with a connection pitch of 125 mm) and D.63 mm (with connection pitches of 140 mm, 190 mm, or 230 mm). Before ordering any part that mentions both diameters, confirm which size your installation uses, as the parts may share a SKU or differ by dimension in ways that are not immediately visible. The fastener positions — hex nut M6 at position 8, washer ISO 10669 at position 7, and washer M6 UNI 6593 at position 16 — are standard metric hardware, but their stainless steel grades (A2 / A4 / AISI 304) differ between positions; always match the grade listed in the description to avoid corrosion incompatibility in a wet pool environment. The PG9 cable gland at position 10 and the screws at position 18 (M4 × 6 mm, A2 stainless) are small components that are easy to overlook during reassembly, so it is worth ordering a spare of each when servicing the motor cover. Where a part is not available to order individually, the complete valve assembly carries the parent factory reference 7038735.