Alfa Laval Unique DV-ST UltraPure Diaphragm Valve

Alfa Laval Unique DV-ST UltraPure diaphragm valve: what it is

The Alfa Laval Unique DV-ST UltraPure is a weir-type hygienic diaphragm valve aimed at pharmaceutical, biotech and other hygiene-critical process lines. It is built from a small set of base parts – valve body, diaphragm, and either a manual handle or a pneumatic actuator – which can be combined into many configurations. Seven Star LLC supplies the Unique DV-ST UltraPure in Oman and the GCC as an independent supplier based in Muscat.

The name tells you the design intent. “DV-ST” identifies the diaphragm valve series, and “UltraPure” marks the execution that is documented to the Alfa Laval Q-doc package, with a low-ferrite body as standard and low surface roughness (Ra) on the wetted parts. Because the exact valve size, body style, diaphragm and actuator are chosen per order, this page describes the range and how to specify it rather than a single fixed configuration.

Technical specifications of the Unique DV-ST UltraPure

How the Unique DV-ST UltraPure works

In the manual version a handle turns the stem, which pushes a compressor down onto the diaphragm. The diaphragm is pressed against the weir in the valve body and the flow path is closed. The handle has standard over-closure protection, which limits the force applied and therefore helps diaphragm life. Steel parts are stainless steel or composite depending on the handle type.

In the pneumatic version an actuator controls the axial movement of a piston, and that movement lifts or lowers the diaphragm. The behaviour on air loss depends on the actuator function: normally closed (NC) springs shut, normally open (NO) springs open, and air/air activated (A/A) uses air for both directions. The Slim actuator (SS/SL) handles normal duties and keeps dead legs short in tight spaces; it can be fitted with an optional stroke limiter for flow control. The High Pressure actuator (SS/HP) is intended for higher product pressures, up to 10 bar depending on the diaphragm material.

Unique DV-ST UltraPure in the valve system

Alfa Laval positions the DV-ST UltraPure beside other UltraPure items such as the LKB UltraPure butterfly valve, the LKC UltraPure non-return valve and the Unique Mixproof UltraPure valve. On a pneumatic valve the actuator can carry the ThinkTop V50 valve control unit, and the range also includes position indicators, stroke limiters and valve positioners. The ThinkTop pulse-seat-clean function is described by the manufacturer as a way to cut CIP liquid use on drain valves.

If your line mixes valve types, tell us the neighbouring models. We can then check that sensing and control units are compatible with every valve on the skid.

Selection checklist for the Unique DV-ST UltraPure

• Process fluid, concentration and whether the line is cleaned with CIP or sterilised with steam (SIP).
• Maximum product pressure, which decides between the SL and HP actuators.
• Diaphragm material: EPDM for continuous steam up to 150 °C, or PTFE/EPDM and M-PTFE where chemical resistance is the priority.
• Valve body: standard low-ferrite body or the optional high-alloy body.
• Body style: two-way, T-valve or tank-outlet, and the connection type and size of the adjacent pipework.
• Operation: manual handle, or pneumatic NC, NO or A/A; ATEX version if the area is classified.
• Feedback and control: none, indicator, ThinkTop unit, or positioner.
• Documentation level needed for qualification and validation.

Installation, commissioning and maintenance

Mount the valve so that the body drains freely; the Slim actuator is designed to make it easier to achieve the correct drain angle in compact skids. Keep the compressed-air supply clean and dry, since the actuator is described as maintenance-free but depends on correct air quality. Verify stroke and indication on commissioning before the first CIP cycle.

The diaphragm is the main wear part. Alfa Laval states that diaphragms carry cure dates and compound tracking, so record the date on installation and change on a planned interval rather than waiting for failure. Over-closure protection on manual handles and a stroke limiter on actuated valves both protect the diaphragm. Keep a spare diaphragm kit for each size in use, with the same material as the installed one, and keep the Q-doc paperwork together with the valve tag for audits.

Typical applications in Oman and the GCC

The DV-ST UltraPure is a pharmaceutical and biotech valve first. In the region that means pharmaceutical plants, hospital and laboratory supply, and purified-water or clean-steam distribution. It is also relevant for beverage, dairy and personal-care producers, and for any clean-utility package attached to a larger industrial site. High ambient temperature, humidity and airborne dust make clean compressed air and sealed actuators important for long service life, and the all-stainless actuator design suits the humid coastal conditions of Muscat and the Batinah region.

Valve configuration table

Information to send with your Unique DV-ST UltraPure RFQ

A complete request avoids back-and-forth and lets us quote the right configuration the first time.

• Valve size, body style and connection type (clamp, weld or other).
• Manual or pneumatic, and the actuator function (NC, NO, A/A).
• Process fluid, temperature, steam use and maximum pressure.
• Diaphragm material and body material required.
• Control unit or positioner needed, and the control voltage.
• ATEX requirement and the qualification documents you need.
• Quantity, project name and required delivery location in Oman or the GCC.

Documents and quotation

Send us the part number Unique DV-ST UltraPure and the intended duty, and we will confirm which official documents are available for it. Pharmaceutical projects normally need the Q-doc package, so state this in your request.

Seven Star LLC is an independent industrial supplier in Muscat serving Oman and the GCC. We quote against the configuration you give us and revert with lead time and availability.