SMC VBAF vs VBA Booster Regulator: Specs, Differences and Replacement Guide

SMC’s VBAF is the newer booster regulator series sitting alongside the long-running VBA. The headline change is not more output. It is a fixed pressure increase ratio with no regulator knob. That one design decision means some VBA units can move to VBAF directly, some need an added regulator, and some have no VBAF equivalent at all. There is also confusion online about which VBA models are being discontinued. This guide uses SMC’s own catalogues to sort it out.

The short answer

VBAF has a fixed boost ratio: 2x for VBAF10 and VBAF20, 4x for VBAF11 and VBAF21. It has no adjustment knob, a built-in silencer, can be mounted horizontally or vertically, and SMC states it is mounting-interchangeable with the VBA series. VBA sets outlet pressure with a knob, mounts horizontally only, and includes 1/2″ models (VBA40A, VBA42A, VBA43A) and air-operated models (VBA22A, VBA42A) that have no VBAF counterpart.

As of 2 November 2026, SMC’s discontinued products page lists only two special models in the booster regulator category: VBA10A-02□-X3239 and VBA11A-02□-X3239, discontinued December 2026, with VBAF named as the replacement. Standard VBA models are not on that list. Check SMC’s latest notice for current status.

What changed in VBAF

Fixed ratio, no knob

SMC’s catalogue puts it plainly: “No longer any need for a pressure regulator knob due to the fixed pressure increase ratio.” Outlet pressure is roughly inlet pressure multiplied by the ratio, limited to the outlet range (0.4–1.4 MPa for the 2x models, 0.8–2.0 MPa for the 4x models). Where a precise set pressure is needed, SMC states that a regulator can be mounted on the VBAF: AR20-□02G-D for VBAF10/11 and AR30-□03G-D for VBAF20/21.

Vertical mounting

The VBA catalogue specifies horizontal installation. VBAF can be installed horizontally or vertically, which helps on crowded machine frames.

Built-in silencer and more compact body

The silencer is integrated, so no external silencer is needed. A D-M9N/P/B auto switch can be mounted on top, and an outlet-side pressure gauge can be fitted.

SMC’s performance claims

These are maximum values under SMC’s test conditions:

• CO2 emissions / air consumption reduced by up to 25% (VBAF10) and 30% (VBAF11);
• maximum flow increased by 10% (VBAF10) and 30% (VBAF11);
• charging time shortened by up to 30% (VBAF10) and 60% (VBAF11), at 0.5 MPa inlet into a 10 L tank;
• service life of 50 million cycles or more.

Sources: SMC VBAF catalogue CAT.ES11-124A; SMC VBAF new product page.

VBAF vs VBA specifications

VBAF figures come from the VBAF catalogue and VBA figures from the VBA standard specifications table. Only the 1/4 and 3/8 VBA models with a VBAF counterpart are shown.

Item	VBAF10	VBAF11	VBAF20	VBAF21	VBA10A-02	VBA11A-02	VBA20A-03
Boost ratio	2x fixed	4x fixed	2x fixed	4x fixed	2x	2–4x	2x
Adjustment	None	None	None	None	Knob with relief	Knob with relief	Knob with relief
Max. flow L/min (ANR)	250	90	1000	300	230	70	1000
Outlet / set pressure MPa	0.4–1.4	0.8–2.0	0.4–1.4	0.8–2.0	0.2–2.0	0.2–2.0	0.2–1.0
Inlet / supply pressure MPa	0.2–0.7	0.2–0.5	0.2–0.7	0.2–0.5	0.1–1.0	0.1–1.0	0.1–1.0
Proof pressure MPa	2.1	3.0	2.1	3.0	3	3	1.5
Port	1/4	1/4	3/8	3/8	Rc1/4	Rc1/4	Rc3/8
Mounting	Horizontal / vertical	Horizontal / vertical	Horizontal / vertical	Horizontal / vertical	Horizontal	Horizontal	Horizontal
Ambient / fluid temp.	2–50 °C	2–50 °C	2–50 °C	2–50 °C	2–50 °C	2–50 °C	2–50 °C
Weight kg	1.0	1.6	4.0	6.3	0.84	0.89	3.9

Sources: SMC VBAF catalogue; SMC VBA catalogue.

Two notes. First, the two catalogues are separate documents, so for generational flow comparisons use SMC’s stated +10% / +30% rather than subtracting table values. Second, VBAF accepts a narrower inlet range than VBA. The 4x models, VBAF11 and VBAF21, top out at 0.5 MPa inlet, so check your plant header pressure before switching.

What a fixed ratio means in practice

With a VBA, technicians are used to turning the knob to a set outlet pressure, and that setting holds reasonably well when inlet pressure moves. With a VBAF, outlet pressure follows inlet pressure. The following points are general engineering guidance; SMC’s catalogue is the reference for any specific case.

• Plants with a fluctuating header: when the compressor unloads or demand peaks, inlet pressure drops and so does VBAF outlet pressure. If the downstream process is pressure-sensitive, add a regulator or stabilise the supply.
• VBAs that were set low: if a VBA was dialled to just a little above line pressure, a 2x fixed VBAF will deliver noticeably more. Add a regulator or re-evaluate the application.
• Systems with tanks and relief valves: confirm that tanks, fittings and relief valves are all rated for the highest outlet pressure the VBAF could reach.
• Inspection routines: without a knob, nobody can “just tweak it”. Record the booster model and expected outlet pressure on the machine’s checklist.

On the other hand, where inlet pressure is stable and the job simply needs a multiple of it, the fixed ratio removes a setting step and stops casual changes to set pressure.

Is the SMC VBA discontinued?

Search results, including some AI summaries, claim that VBA10A and VBA11A are discontinued. That is not what SMC’s own page says. The booster regulator category on SMC’s discontinued products page lists only:

Discontinued model	Discontinuation	Replacement named by SMC
VBA10A-02□-X3239	December 2026	VBAF
VBA11A-02□-X3239	December 2026	VBAF

Source: SMC discontinued products, booster regulators, checked 2 November 2026.

The -X3239 suffix marks a special version. Standard VBA10A, VBA11A and other VBA models are not listed. If your unit carries the -X3239 suffix, ask SMC which VBAF model to use.

Model-by-model replacement check

“Corresponds” below means the port size and ratio line up. You still need to check pressure ranges against your application.

Current model	VBAF option	Notes
VBA10A-02 (1/4, 2x, knob)	VBAF10 (1/4, 2x fixed)	Outlet no longer adjustable. VBA10A sets 0.2–2.0 MPa; VBAF10 outlet 0.4–1.4 MPa, inlet 0.2–0.7 MPa
VBA11A-02 (1/4, 2–4x)	VBAF11 (1/4, 4x fixed)	VBAF11 inlet 0.2–0.5 MPa, outlet 0.8–2.0 MPa. If you ran somewhere between 2x and 4x, add a regulator
VBA20A-03 (3/8, 2x)	VBAF20 (3/8, 2x fixed)	VBA20A sets 0.2–1.0 MPa; VBAF20 outlet 0.4–1.4 MPa. Add a regulator if you need to cap outlet pressure
3/8 port needing 4x	VBAF21 (3/8, 4x fixed)	No 3/8 4x model exists in the VBA series, so this is a new option
VBA40A / VBA43A (1/2″)	None	VBAF only comes in 1/4 and 3/8. Stay with VBA
VBA22A / VBA42A (air-operated)	None	No air-operated VBAF. Stay with VBA
VBA10A-02□-X3239 / VBA11A-02□-X3239	VBAF (SMC’s named replacement)	Confirm the exact model with SMC

For model-level background, see our articles on the VBA10A-02GN, the VBA10A-F02, and the 1/2″ VBA43A-04GN and VBA40A-F04GN, which have no VBAF equivalent.

VBAT air tanks and mounting hardware

VBAF can be mounted on a VBAT air tank, but not every combination works. The table reproduces the compatibility chart in SMC’s VBAF catalogue (● = can be combined):

Air tank	VBAF10 / VBAF11	VBAF20	VBAF21
VBAT05A(1) / VBAT05S(1)	●	—	—
VBAT10A(1) / VBAT10S(1)	●	●	●
VBAT20A(1)	—	●	—
VBAT20S(1)	—	●	●
VBAT38A(1)	—	●	—
VBAT38S(1)	—	●	●

Source: SMC VBAF catalogue.

• Mounting bolts: VBAF10/11 use the bolts supplied with the VBAT. VBAF20/21 need option “B”, or the separate bolt kit KT-VBAF20-3 (4 bolts).
• Confirm the tank’s operating pressure range covers the boosted outlet pressure, especially with 4x models.

For more on SMC receivers, see our VBAT05A1-EV-X105 air receiver article.

When VBA is still the better fit

• You need a 1/2″ port and higher flow (VBA40A, VBA43A).
• You set outlet pressure remotely with pilot air (VBA22A, VBA42A).
• Header pressure is above the VBAF inlet limit, or you need wide manual adjustment.
• You are replacing one failed standard VBA like for like.

For new machines, vertical installs, faster tank charging or lower air consumption, VBAF is worth evaluating first.

Whichever series you choose, the booster only multiplies the air it receives. Water, oil and particles in the supply end up in the booster and the tank downstream, so a proper filter-regulator-lubricator setup upstream is part of the job. Our guide to FRLs for compressed air preparation covers the basics, and it is worth checking before you commission a new booster or tank.

What to have ready

1. Full model number of the existing VBA, including any suffix such as -X3239, and a nameplate photo.
2. Plant inlet pressure, minimum and maximum.
3. Required outlet pressure, and whether it must be precisely set.
4. Required flow, or the downstream cylinder and tank volumes.
5. Whether a VBAT tank is fitted, and which one.
6. Available space and mounting orientation.

Email us those details and we will help you check the technical fit.

FAQ

Can a VBAF go where the VBA was?

SMC states VBAF is mounting-interchangeable with the VBA series. Outlet pressure is not adjustable and the inlet range differs, so check the application first.

Can VBAF11 take 0.7 MPa inlet?

No. SMC lists 0.2–0.5 MPa inlet for VBAF11/21 and 0.2–0.7 MPa for VBAF10/20.

Is there a 1/2″ VBAF?

No. VBAF comes in 1/4 (VBAF10/11) and 3/8 (VBAF20/21) only.

Will my existing VBAT tank work?

Some combinations do. Use the compatibility table above and confirm the tank’s pressure rating.

How long does a VBAF last?

SMC states 50 million cycles or more under its test conditions.