STAUFF tank filler breathers, types SPB and SMBB, plastic and metal

Compare its oil displacement figure with how fast oil actually leaves your reservoir. STAUFF quotes it directly for that purpose: the SPB covers 1000 l/min / 264 US gpm and the SMBB-47 covers 400 l/min / 106 US gpm. The matching air flow rates are 1.00 and 0.40 m3/min. Undersize it and the tank either draws air past the seals or pulls a partial vacuum against the pump — and a fine filter element makes that worse, not better.

Pick it on where the machine lives, not on the oil. 10 µm foam is the standard and right for ordinary industrial surroundings. 40 µm suits clean environments or where air flow is the priority. 3 µm — glass-fibre pleated on the SPB, filter paper on the SMBB — is for genuinely dusty and abrasive places like cement, quarrying and grinding shops. Remember that a finer element passes less air, so check it still covers your oil displacement.

Air flow decides first: the plastic SPB moves two and a half times the air of the metal SMBB. After that, the SPB is the one that can be pressurised and the only one that takes a dipstick; the SMBB-47 is smaller, is steel rather than polyamide so it stands knocks better, and is the only one offered chrome-plated or epoxy-coated. On a large reservoir it is usually the SPB; on a small power pack, the SMBB.

It stops returning oil splashing up into the breather from below. That matters because oil on the element blinds it — the air path closes up and the tank stops breathing properly, which is the failure nobody notices until seals start weeping. It is fitted as standard on the SPB and has to be actively ordered out. The plastic dipsticks have the same feature integrated.

Yes, but there is a rule: the dipstick must be at least 15 mm / 0.59 in shorter than the basket. Otherwise it fouls the bottom of the strainer and neither part works properly. Since the dipstick can be cut down and the basket cannot, the sensible order is to size the basket for the tank and then trim the dipstick to keep that 15 mm of clearance.

Only if the tank was built for it. Pressurisation — 0.2, 0.35 or 0.7 bar on the SPB — cuts the volume of ambient air drawn in, which in a humid climate mostly means less moisture condensing onto the oil. But it loads every seam, seal and sight glass on the reservoir, including the level gauge, which is limited to 2 bar. Confirm the whole tank before specifying the 0.7 bar setting. And note that no pressurisation is available on the metal SMBB.

The plastic SPB is rated minus 40 to plus 120 degrees C (minus 40 to plus 248 degrees F), which is a wider range than most people expect from a polyamide part — the body and cap are glass-fibre reinforced. For the metal SMBB, the sealing is cork rather than NBR and STAUFF asks to be consulted on temperature, so tell us the duty and we will confirm it rather than assume.

Depends on the version. The SPB 4 needs only the aperture — it clamps in with three clamping jaws. The SPB 5 needs a six-hole pattern on a 73 mm bolt circle around a minimum 63 mm aperture, to a flange interface similar to DIN 24557 part 2. The SMBB-47 needs three M5 holes on a 41 mm circle around a 28 mm aperture. Allow 122 mm of clear mounting space around an SPB so the cap can be turned.

Because the screws supplied with the SPB 5 are sheet metal screws that form their own thread as they go in, so the hole has to suit the material they are forming. STAUFF recommends 4.0 mm at 1.20 mm sheet, 4.1 mm at 2.00 mm, 4.3 mm at 4.00 mm and 4.4 mm at 5.00 mm. Too small and the head shears off; too large and it never grips. If you would rather not rely on that, the supplied screws can be replaced by M5 socket cap screws into tapped holes.

Yes. The SPB 5 comes with six sheet metal screws (ISO 7049-St 4.8x16-C-H) and the SMBB-47 with three slotted pan head screws (ISO 1580 M5x12-5.8). Both can be substituted — M5 socket cap screws to ISO 4762 on the SPB, regular M5 bolts on the SMBB — if your build standard prefers a cap head or a tapped hole.

On a schedule rather than on symptoms, because the symptom of a blinded element is a tank that struggles to breathe, and by then it has already been drawing air past seals. The interval depends entirely on the environment — a clean assembly hall and a cement plant are not comparable. A pleated element holds more dirt than foam at the same rating, so it buys longer intervals on a dirty site. Keep spares on the shelf; it is the cheapest part on the reservoir.

Yes — STAUFF invites enquiries for alternative materials and micron ratings on both families, and for alternative body materials on the SPB. If your site standard names a rating that is not in the list, or the fluid or environment is unusual, send the detail and we will come back with what is available rather than substituting the nearest catalogue item.