BTL NON-RISING STEM GATE VALVE| MODEL: Z45X-10/16

The BTL handwheel-operated non-rising stem gate valve, Model Z45X-10/16, is an ideal solution for underground pipelines and installations with limited space. Unlike the rising stem gate valve, the stem of this valve sits entirely inside the valve body and does not rise or lower during operation. This design saves a great deal of installation space, making the valve well suited to underground valve pits, technical basements, and pipelines running close to building ceilings.

Construction of the BTL Z45X-10/16 non-rising stem gate valve

The BTL non-rising stem gate valve has a distinctive design in which the threaded stem is not exposed. When the valve is opened or closed, the stem simply rotates in place without moving up or down.

The Z45X-10/16 consists of the following main components:

Dimension table of the BTL Z45X-10/16 non-rising stem gate valve

Operating characteristics and installation locations of the non-rising stem gate valve

Characteristics of the BTL non-rising stem gate valve

Unlike the rising stem valve, whose drive thread is located outside, the non-rising stem gate valve has its thread fully inside the valve cavity, immersed in the medium. When the handwheel is turned, the stem only rotates in place rather than moving up and down. The threaded motion takes place directly where the stem engages the wedge, pulling the wedge up or pushing it down to open or close the flow.

Because the drive thread is in direct contact with the medium, this component is prone to corrosion, so the stem is usually made of stainless steel. In addition, non-rising stem valves are harder to lubricate and maintain than rising stem valves. This is a technical trade-off made in exchange for a compact design that optimizes space.

Furthermore, the fully EPDM-encapsulated wedge allows the valve to seal tightly and quietly and to prevent leakage effectively, without depending on the machining precision of a conventional metal seat.

Suitable installation locations

Since no clearance is needed above the valve for a rising stem, the BTL non-rising stem gate valve is suitable for:

• Underground installation (valve pits, valve chambers, buried outdoor water supply lines): This is the most common application for non-rising stem gate valves, because the valve pit does not need to be dug deeper or built taller to accommodate the stem travel.
• Spaces with low ceilings, narrow indoor technical shafts, basements, and technical corridors.
• Urban water supply networks and underground fire protection (PCCC) systems: where valves are usually installed in covered manholes and their status does not need to be checked visually on a regular basis. In particular, when installed in fire protection systems, non-rising stem gate valves are usually fitted with an additional OS&Y-type signal sensor to quickly detect the open/closed status of the valve remotely.

Operation and maintenance notes for the non-rising stem gate valve

• The drive thread is immersed in the medium, so deposits and corrosion can build up over time. If the water source is not clean, the valve may seize when left unoperated for a long time. For valves permanently installed and rarely operated, we recommend periodic test operation (every 3–6 months) to avoid the situation of “left untouched for too long, then seized and impossible to turn when an emergency shut-off is needed.”
• Periodically inspect the gasket and the bonnet bolts. This is the area under direct pressure and the most common leak point on gate valves in general.
• Do not use a gate valve to throttle flow for extended periods. Use it only for fully open or fully closed service.

Comparison: BTL non-rising stem vs. rising stem gate valves

An Phú Thành specializes in distributing genuine BTL gate valves with complete CO, CQ, and catalogue documentation. If you need detailed consultation or a special project quotation, please contact hotline/Zalo 0946 729 913. The experienced team at An Phú Thành looks forward to assisting you.