Glass Valves
Glass Valves
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Full technical data and dimensions
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Zero Holdup Bottom Outlet Valve
Glass bottom outlet valve that drains a vessel completely
Borosilicate glass bottom outlet valve that seats flush with the vessel floor, so no product is left standing in the outlet when the vessel is drained.
| Product type | Glass bottom outlet valve, zero holdup |
|---|---|
| Material | Borosilicate 3.3 |
| Pressure rating | Not published on the valve catalogue page — confirm with us for your duty |
| Temperature rating | Not published on the valve catalogue page — confirm with us for your duty |
| Holdup volume | Zero — the plug seats flush with the vessel floor |
| Operation | Manual, knurled handwheel with adjusting collars |
| Dimensions | Customised according to requirements |
Product overview
What it does, and where it fits.
A bottom outlet valve exists so a vessel can be emptied properly. Zero holdup names the thing that separates this build from an ordinary outlet valve: the plug closes flush with the inside of the vessel floor, so when the valve is shut there is no cavity underneath holding product back.
That matters most on batch work. Any pocket below the vessel floor keeps a little of the last charge — it settles, it degrades, and it carries into the next batch. Zero holdup removes the pocket rather than trying to flush it out afterwards, which is why this build gets specified on reactors running actives, colour-critical products, or anything where batch-to-batch carryover has to be ruled out rather than merely reduced.
The body is borosilicate, so the seat and the outlet stay visible in service — an operator can see that the valve has actually cleared instead of inferring it from flow. It is operated by hand from below, with no actuator or air supply to route under the vessel.
This valve is not built to a fixed size list. Dimensions are customised according to requirements, so the vessel connection, the side outlet and the seat are made to suit the vessel it goes on. Send us the nozzle detail and the duty and we will confirm the build.
Features
Built into every unit.
- Plug seats flush with the vessel floor — no cavity left to hold product back
- Complete drainage between batches, so nothing carries into the next charge
- Borosilicate glass body — the seat and the outlet stay visible in service
- Side outlet carries the discharge line away from directly under the vessel
- Hand operated from below; no actuator or air supply required
- Dimensions customised according to requirements — built to suit the vessel it goes on
Benefits
Why it earns its place in the line.
- No residual volume at the vessel outlet — carryover is designed out, not washed out
- Nothing settles or degrades in a dead pocket between batches
- Fully transparent — the operator can see the valve position and the media through the body
- Inert to almost all process media; no metal in the wetted path
- PTFE spindle: no lubrication, no seizing, no contamination of the batch
Applications & industries
Where it is specified.
Typical applications
- Reactor and receiver draining where no residue may remain
- Batch processes with strict cross-contamination limits
- Slurries and crystallising products that would settle in an outlet
- Bottom sampling and complete discharge from a glass vessel
Industries served
- Chemical processing
- Pharmaceutical
- Fine chemicals & dyes
- Water & effluent treatment
- Distillation & solvent recovery
- Research & pilot plant
- Agrochemicals
Technical data
Specification for Zero Holdup Bottom Outlet Valve.
Figures below are for this product only — every item in the range carries its own dimension table.
| Product type | Glass bottom outlet valve, zero holdup |
|---|---|
| Material | Borosilicate 3.3 |
| Pressure rating | Not published on the valve catalogue page — confirm with us for your duty |
| Temperature rating | Not published on the valve catalogue page — confirm with us for your duty |
| Holdup volume | Zero — the plug seats flush with the vessel floor |
| Operation | Manual, knurled handwheel with adjusting collars |
| Dimensions | Customised according to requirements |
FAQ
Questions we are asked about this item.
That there is no cavity below the vessel floor when the valve is closed. The plug seats flush with the inside of the vessel, so no product is left standing in the outlet once the vessel has been drained.
Both close at the vessel rather than below it, so neither leaves a dead leg under the nozzle. This is the zero holdup build, specified where no residual volume at all is acceptable. If you are choosing between the two, send us the vessel detail and the duty and we will advise.
There is no fixed size list for this valve — dimensions are customised according to requirements. Tell us the vessel nozzle size, the outlet you need and the duty, and we will build it to suit.
Related products
Commonly specified alongside Zero Holdup Bottom Outlet Valve.
Enquiry
Tell us your line size — we'll confirm the spec.
Send the bore, the media, the temperature and pressure, and the flange standard you work to. Drawings and custom sizes welcome.
Not sure which spec fits your process?
Send your requirement — media, temperature, pressure, dimensions — and we'll recommend the right product or fabricate it.
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