Deep page · not in the main menu
Thread and gasket decoder for everything that screws onto a tote
"What fitting do I need?" is the most common tote hardware question. This page is that answer, written down once, including the gasket materials that matter as much as the thread.
Need a fitting identified?
Describe the fitting in the message field — the thread, the measurements and what you want to connect. A partner supplier follows up.
Searchable thread and gasket index
Type a size, a material or a symptom.
- 2" NPS / NPT maleMost Schütz and Mauser discharge valves in North America. Takes a 2" female garden or camlock adapter.
- 2" BSP maleEuropean-built bottles, common on imported Werit and older Schütz units. Do not force an NPT fitting into it.
- 2" Buttress (coarse)Found on butterfly-valve outlets. Needs a buttress-to-NPT reducer.
- 3" Camlock (Part A)Fast-fill and fast-drain setups; pairs with a 3" Part C coupler on your hose.
- 6" (DN150) lid, coarse threadStandard fill cap on 275 and 330 gal totes. Vented and non-vented versions, EPDM or Viton gasket.
- 9" (DN225) lidLarge manway used on some 330 and 550 gal bottles and most rebottled units.
- 61 mm screw capSmall vent or sample port on select food-grade bottles. Usually paired with a tamper-evident seal.
- S70x6 (DIN 61) coarseMetric cap thread on European bottles; adapters to 2" NPT exist but check the gasket material.
- Tri-clamp 2" ferruleRetrofit on stainless IBCs and brewery totes.
- EPDM gasketDefault seal: water, caustics, most detergents. Not for hydrocarbons.
- Viton (FKM) gasketFor many solvents, fuels and acids. Check chemical compatibility for your product before you specify it.
- Buna-N (nitrile) gasketOils, lubricants, greases. Cheap and tough, poor with strong oxidisers.
Outlet threads in detail
| Thread | Where you find it | Mates with | Watch out for |
|---|---|---|---|
| 2 in NPS male (straight) | Many North American valves | 2 in NPS/NPT female adapters, camlock adapters | Seals on a gasket; do not over-torque |
| S60x6 coarse (buttress) | Many European-built valves | S60x6 caps and adapters | Coarse 6 mm pitch; does not mate with NPS or NPT |
| 2 in BSP male | Some European fittings | 2 in BSP female fittings | 55° thread; not interchangeable with NPT |
| Camlock (Part A) outlet | Fast transfer setups | Matching Part C or D coupler | Check the gasket in the coupler, not the tote |
| 2 in tri-clamp ferrule | Stainless IBCs and retrofits | 2 in clamp and gasket | Gasket material must suit cleaning temperature |
Lids and caps
| Cap | Diameter | Typical use | Options |
|---|---|---|---|
| DN150 / 6 in | 150 mm | Standard fill lid on 275 and 330 gal | Vented, solid, tamper-evident |
| Larger lids (around 225 mm) | ≈225 mm | Some designs, for easier cleaning and filling | Vented or solid |
| Manway | Varies | Stainless IBC access | Gasketed; size varies by maker |
Vented lids matter more than people expect. Gravity-discharging a tote through a solid lid pulls a vacuum that makes the bottle "glug", slows flow and can deform the bottle wall. A vented lid fixes it.
Gasket selection by chemistry
| Material | Generally good with | Generally avoid | Approx. temp limit |
|---|---|---|---|
| EPDM | Water, caustics, detergents, glycols, dilute acids | Hydrocarbons, solvents, oils | −40 to 250 °F |
| Viton (FKM) | Many solvents, fuels, strong acids | Ketones, amines, hot water/steam | −15 to 400 °F |
| Buna-N (nitrile) | Oils, greases, lubricants, diesel | Strong oxidisers, ozone, ketones | −30 to 250 °F |
| Silicone | Food contact, high-temperature dry service | Solvents, fuels | −80 to 400 °F |
| PTFE | Most chemistry, aggressive service | Poor sealing on rough surfaces | −100 to 450 °F |
A general guide only: confirm compatibility for your exact product and concentration with the gasket maker’s chart and the SDS. Choosing the right elastomer is an inexpensive way to prevent leaks.
Questions people actually ask
What thread is an IBC tote outlet?
Usually 2 inch. North American valves commonly have a 2 inch NPS male outlet, while European-built valves often use the coarse S60x6 thread and need an adapter for NPT fittings.
Can I use NPT fittings on a BSP outlet?
No. NPT uses a 60° thread form and BSP a 55° form with a different pitch at 2 inch. They will start to engage and then leak or gall the thread. Use the correct fitting or an NPT-to-BSP adapter.
Why does my tote glug when draining?
The bottle is pulling a vacuum through a solid lid. Fit a vented lid or crack the cap slightly and flow becomes smoother and faster.
Adapter chains: getting from what you have to what you need
The common question is not "what thread is this" but "what do I need to connect it to my hose".
| From | To | Parts needed |
|---|---|---|
| 2 in NPS male (tote valve) | 3/4 in garden hose | 2 in adapter → GHT adapter |
| 2 in NPS male | 2 in camlock Part C hose | 2 in adapter → camlock Part A |
| 2 in NPS male | 1 in pump inlet | 2 in adapter with 1 in reducer |
| S60x6 coarse (European valve) | 2 in NPT fittings | S60x6 → NPT adapter |
| S60x6 coarse | Garden hose | S60x6 adapter + GHT adapter |
| 2 in BSP male | 2 in NPT fittings | BSP → NPT adapter |
| 6 in DN150 lid | Fill hose | Lid adapter with a hose port |
| 6 in DN150 lid | Top-entry pump | Pump adapter plate |
| Tri-clamp 2 in (stainless) | 2 in NPT | Clamp × NPT ferrule adapter |
Every adapter in a chain is a leak path and a restriction. Two adapters is normal; four usually means a different valve would be simpler. Pricing for fittings is by quote from partner suppliers.
Thread identification without a gauge
You can identify most tote threads with a ruler and a straight edge.
Step 1 — check the pitch. Measure one inch along the thread and count the crests. A coarse thread with only about four crests per inch (a 6 mm pitch) is S60x6. 2 inch NPT and NPS are 11.5 threads per inch; 2 inch BSP is 11.
Step 2 — tapered or parallel? Lay a straight edge along the crests. If they fall away from the edge, it is tapered (NPT or BSPT). If they stay parallel, it is a straight thread such as NPS, BSPP or S60x6.
Step 3 — look at the thread form. NPT and BSP crests are symmetrical vees (60° and 55°). A buttress thread such as S60x6 has one steep flank and one shallow flank — once you have seen one you cannot mistake it.
Step 4 — measure the outside diameter. A 2 inch NPT male measures about 2.375 inches across the crests and a 2 inch BSP male about 2.35. An S60x6 male is about 60 mm (2.36 in) — similar, which is why pitch is the better test.
And the shortcut
Describe the thread and your measurements in a free quote request, and a partner supplier can help match the fitting.
Thread and fitting questions
Should I use PTFE tape on a tote valve?
On a tapered NPT thread, yes — a few wraps in the direction of tightening. On a straight thread that seals on a gasket or washer at the face, tape on the threads does nothing useful.
How tight should a tote fitting be?
Hand tight plus a modest turn with a wrench, unless the maker gives a figure. Over-tightening crushes the gasket into a permanent set that weeps later.
Can I leave an adapter permanently fitted?
Yes, and it is usually better than repeatedly making and breaking a threaded joint. Just cap the open end so debris cannot get in.
What is a vented lid and do I need one?
A lid with an air path that lets air in as liquid leaves. If you gravity-discharge at all, you need one — flow improves and you stop deforming the bottle by pulling a vacuum.
Valve types compared, not just thread sizes
The thread gets you connected; the valve type decides whether you enjoy using it.
| Type | Flow | Throttling | Best for | Weakness |
|---|---|---|---|---|
| 2 in butterfly | Good | Poor | Standard duty, thin liquids | Disc obstructs flow slightly |
| 2 in ball, full port | Excellent | Fair | Viscous product | Bulkier |
| 2 in gate | Excellent | Good | Slurries, solids in suspension | Slow to operate |
| Camlock outlet | Excellent | None | Fast transfer | No flow control on its own |
| 2 in diaphragm | Fair | Excellent | Metered dosing | Restricts flow |
| Tri-clamp ball (stainless) | Excellent | Fair | Sanitary service | Requires ferrule |
Pricing for valves and fittings is by quote from partner suppliers.
Gasket failure modes, and how to recognise each
Chemical swelling
The gasket has grown and feels soft or tacky. Cause: the wrong elastomer for the product. Look for weeping that starts days or weeks after the fill rather than immediately.
Compression set
The gasket is flattened and has taken a permanent shape. It no longer springs back when pressed. Cause: over-tightening, or long service at high temperature. It may seal when warm and weep when cold.
Thermal degradation
Hardened, brittle, sometimes cracked across the section. Cause: service above the material’s temperature limit, or repeated hot fills. The material has aged rather than reacted.
Ozone and UV cracking
Fine surface cracks, usually on the exposed face only. Cause: an uncapped valve sitting outdoors for months. Easy to prevent with a dust cap.
Physical damage
A nick, a tear or a pinch line. Cause: assembly. Inspect the gasket and the seat before seating it, every time.
Genuinely worn out
Uniform loss of resilience with no chemical or thermal signature. Less common than the causes above — a failed gasket usually has a reason.
More fitting questions
How often should gaskets be replaced?
Whenever the valve or fitting comes off, as a matter of course, and whenever the product changes to a different chemical family. In continuous service, inspect them regularly and replace at the first sign of swelling, cracking or set.
Can I use plumber's tape on a BSP thread?
On a parallel BSP (BSPP) thread it will not help: it seals on a washer or O-ring at the face, not on the thread flanks. Tape on the threads just makes assembly harder.
What is the difference between NPS and NPT?
NPS is straight (parallel), NPT is tapered, with the same thread form and pitch. Tote outlets are often NPS but commonly connect to NPT-style fittings that seal on a gasket rather than the thread — which is why the gasket matters as much as the thread standard.
Are camlocks worth the conversion?
If you connect and disconnect several times a day, usually yes — a camlock is a seconds-long connection against repeated threading, and it is easier on the outlet thread.
Where people go from here
Reuse first, then recycle.