Threaded-lug valve bodies for separately bolted flange connections
Our gear-operated lug butterfly range covers nominal sizes from 2 to 12 in. in PN10 and PN16 selections. Threaded bosses around the body accept the bolts from each mating flange. The order identifies the lug connection, operator and service duty together, including any requirement for end-of-line isolation.
| Valve body | Lug-style butterfly valve with threaded mounting bosses |
|---|---|
| Catalog nominal range | 2–12 in. / DN50–300 |
| Pressure designation | PN10 or PN16 for the selected valve assembly |
| Flange fastening | Separate flange bolts into the valve-body lugs |
| Operator | Worm gearbox and handwheel |
| Catalog temperature band | 0–100°C, with seat and medium suitability checked for the order |
| End-of-line duty | Only a selected model with an explicit applicable duty rating |
Match the valve size and DN on every schedule line before selecting the lug and flange details.
| Nominal valve size (in.) | Nominal DN | PN selections |
|---|---|---|
| 2 | 50 | 10 / 16 |
| 2-1/2 | 65 | 10 / 16 |
| 3 | 80 | 10 / 16 |
| 4 | 100 | 10 / 16 |
| 5 | 125 | 10 / 16 |
| 6 | 150 | 10 / 16 |
| 8 | 200 | 10 / 16 |
| 10 | 250 | 10 / 16 |
| 12 | 300 | 10 / 16 |
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Nominal-size cross-reference within the 2–12 in. catalog range. Pipe OD, lug-thread size and bolt-circle dimensions come from the selected lug-valve drawing.
The catalog lists PN10 and PN16 valve selections. Removing the downstream pipe can create a different loading and sealing duty; the selected model needs an explicit rating for that arrangement.
The flange standard and nominal size establish the joint to be matched. The valve drawing then identifies the lug threads and bolt layout.
A fire-water, drinking-water or other approved service must be named in the order. We identify the proposed manufacturer, model and required records with that offer.
Each mating flange attaches to the body lugs. This differs from a wafer valve’s long through-bolts and gives the installation its own bolt-length and access requirements.
The bolt must engage the intended thread length without bottoming or interfering with the opposite connection. Flange thickness and washers form part of that length calculation, so bolt length is worked out for each joint.
If one pipe section will be removed while the valve remains in place, identify that condition on the valve schedule. The selected model and installation details must cover the required pressure, direction and supported arrangement.
A valve can fit the flange gap but leave the handwheel against a wall or access platform. The operator drawing is part of the fit check, particularly where the gearbox orientation is restricted.
A separately bolted flange arrangement can suit equipment connections that need a defined dismantling plan. The valve’s permitted duty and the supports around the joint still control the maintenance procedure.
Skid layouts often constrain bolt access and handwheel position. Including the adjoining flange and equipment envelope helps resolve those interfaces before the valve is packed.
Different lug threads or flange patterns can sit within the same nominal valve size. Separate stock descriptions for body, pressure designation and connection details reduce receiving and resale errors.
Compare wafer valve clamping arrangements
Damaged starts, contamination and coating in the threads can prevent correct bolt engagement. A bolt forced into a damaged lug can compromise the joint before the valve reaches service.
The open disc needs room within the adjoining flange and pipe bore, including any lining or nearby fitting.
Gearbox stops, handwheel movement and position indication belong to the supplied assembly check. Any switch package is identified separately so the receiving team knows what the valve line includes.
The selected model, size and pressure designation need to agree across the drawing, required test records and item identification. An end-of-line requirement must be supported by the offered model’s applicable documentation.
We quote the valve-and-gearbox assembly separately from mating flanges, bolts, washers and other connection items. Where fasteners are included, their thread and length stay tied to the selected valve drawing.
Packing protects the lug threads from impact and debris while bore covers shield the seat and disc. The body is supported so the gearbox and handwheel stay clear of load-bearing contact.
Size, body style and project item reference stay with the valve line and packing list. The quotation states the agreed batch quantities and shipment terms for the destination, without substituting a general catalog lead time.
Choose the body connection that fits the installation and its planned dismantling method.
| Detail | Lug body | Wafer body |
|---|---|---|
| Flange fastening | Bolts from each flange engage body lugs | Through-bolts clamp both flanges around the body |
| Bolt selection | Thread form and engagement length are critical | Length follows the full flange/valve stack |
| One-side pipe removal | Requires the model’s applicable duty rating and arrangement | Do not remove the clamping needed to retain the valve |
| Fit drawing | Lug layout, threads, face spacing and disc sweep | Locating arrangement, seat faces and disc sweep |
Chemical compatibility, pressure-temperature limits and product approvals are specific to the supplied valve assembly.
See wafer butterfly valve detailsNo. Threaded lugs alone do not establish end-of-line capability. That duty needs an applicable rating for the selected valve model, pressure and direction, together with the manufacturer’s specified installation and support arrangement.
The valve body and gearbox are not substitutes for pipe supports. The installation arrangement must carry the connected pipe loads without forcing the valve into alignment; allowable external loads and support points follow the selected valve instructions and piping design.
Lug holes take flange fasteners; they are not process-pipe connections. Use the bolt-thread specification on the selected valve drawing. Do not choose fasteners from the nominal pipe size or assume a particular inch or metric pitch.
The designations describe different rating systems and should not be treated as interchangeable. Flange drilling may be available to a named pattern, but the valve pressure-temperature limits and the required connection must both match the order.
Yes. The gear-operated valve and handwheel can be itemized as the valve assembly. If electrical monitoring is needed, its switch, bracket and contacts are a separate specified package; they are not implied by the gearbox.
Follow the installation instructions for the selected seat and body design. Some resilient seats form the flange seal and do not use additional gaskets. Adding a gasket without the specified arrangement can change seat compression and interfere with operation.
Other items in the same product category.
We wrote these for buyers specifying and receiving exactly this kind of package.
Send your valve schedule, flange standard and service conditions. Include any planned one-side pipe removal so the proposed assembly and its duty documentation can be reviewed with the order.