SMC Pneumatics, New Zealand

RFQ / SMC

CQ2 and CDQ2 are the same cylinder. The D means there is a magnet in the piston, and without it the auto switches on your machine will never see anything. One letter, in the middle of the part number, and it is the most common wrong order on this brand.

SMC is on most imported machinery in New Zealand, particularly from Japan and increasingly from China. It is a huge catalogue built out of configurable part numbers, which is why a part number that is one character out still looks right.

Request a quote

Reference pages

Page	Covers
Cylinders and auto switches	The D that means magnet, reading bore and stroke, choosing auto switches by NPN, PNP or two wire, speed controllers and why meter-out matters, and the lubrication mistake that destroys cylinders

The D means magnet

The single most valuable thing on this page.

SMC inserts a D into the series code to indicate a built-in magnet for auto switches. Everything else about the cylinder is unchanged.

Without magnet	With magnet	Family
CQ2	CDQ2	Compact cylinder
CM2	CDM2	Round body cylinder
CJ2	CDJ2	Mini cylinder
MB	MDB	ISO cylinder
MGP	MGPM and similar	Guided cylinder

The two cylinders are identical to look at. Same bore, same stroke, same mountings, same ports. The one without a magnet strokes perfectly and produces no position signals at all.

So the failure presents as a sensor fault or a PLC fault. The cylinder moves, the machine sequence hangs waiting for a signal, and everybody looks at the switch.

It cannot be added later. The magnet is on the piston, inside the cylinder.

Two rules that prevent it:

If there are switches clamped to the cylinder body, the replacement needs the D. Look before you order.

And send the whole part number, not the series. The difference between a working replacement and a useless one is one character.

Festo has exactly the same trap in different notation, which is on our Festo cylinders page. If your plant runs both, it is worth knowing both.

The families

Cylinders and actuators

Series	What it is
CQ2, CDQ2	Compact cylinder. Very high volume
CM2, CDM2	Round body cylinder
CJ2, CDJ2	Miniature cylinder
MB, MDB, C95, C96	ISO 15552 cylinders
MGP	Compact guide cylinder
MXS, MXQ	Slide tables
MY, CY1	Rodless cylinders
CRB2, CRA1	Rotary actuators
MHZ2, MHL2, MHC2	Grippers

Valves and manifolds

Series	What it is
SY3000, SY5000, SY7000	The volume solenoid valve range
SV1000 to SV4000	Valve range for manifolds
VQ, VQC	Compact valves and manifolds
VF, VFS, VZ, VT	Other valve families
SS5Y, SS5V, VV5Q	Manifold base numbers. Configured assemblies
EX600, EX500, EX260, EX250	Serial and fieldbus interface units
VXD, VXZ, VNB	Process and media valves

Air preparation and fittings

Series	What it is
AC20, AC30, AC40, AC50	Modular F.R.L. combination units
AF, AR, AL, AW	Filter, regulator, lubricator, filter regulator
AFD, AMD	Mist separators and micro mist separators
AV, VHS	Soft start and lockout valves
AS	Speed controllers
KQ2, KQB2, KJ	One-touch fittings
TU, TIU, TRB	Tubing

Sensors and vacuum

Series	What it is
D-M9, D-A9	Cylinder auto switches. Solid state and reed
ISE, ZSE, PSE	Pressure and vacuum switches
PF2A, PF2W	Flow switches
ZK2, ZB, ZX	Vacuum ejectors
ZPT, ZP	Suction cups

Electric actuators and thermo

Series	What it is
LEY, LEF, LEFS, LEL	Electric actuators and slides
LEHZ, LEHF	Electric grippers
LECP, LECA, JXC	Actuator controllers. Matched to the actuator
HRS, HRSH, HRZ	Thermo chillers

Electric actuators are a matched set of actuator, controller and cable, like any servo product. Send all the numbers.

Do not add a lubricator to a modern system

Counterintuitive, widely got wrong, and it destroys cylinders.

Modern SMC cylinders and valves are pre-lubricated at the factory and are designed to run on clean dry air with no added oil.

Action	Result
Running non-lube components on clean dry air	Correct. That is the design
Adding an oiler to help them along	The oil washes out the factory grease
Then stopping the oiler, or letting it run dry	Nothing left. Rapid wear
Genuinely lubricated system, kept lubricated	Fine, but it must never be allowed to stop

The dangerous version is starting lubrication and then stopping it, which is what happens when a lubricator empties and nobody notices, or when a machine is moved to a different air leg.

So on a plant where cylinders have started failing early: find out whether somebody added an oiler, and whether it has run dry. That is free to check and it explains a lot of repeat failures.

Clean, dry, filtered air is what these components want. Effort spent on the dryer and the filter element is worth more than effort spent on lubrication.

Speed controllers, and why meter-out matters

Genuinely useful, and it explains a class of fault that gets blamed on cylinders.

A cylinder's speed is set by restricting the air, and it matters which side you restrict.

	Meter-out	Meter-in
Restricts	The exhausting side	The incoming side
Motion	Smooth and controlled	Prone to lurching and stick-slip
Normal choice for a cylinder	Yes	Rarely

Meter-out keeps a cushion of back pressure in the cylinder, which is what makes the motion smooth. Meter-in lets the cylinder lurch forward and then wait for air, which on a light or vertical load produces a jerky stop-start motion.

So a cylinder that lurches, judders or overshoots is often a speed control arrangement rather than a worn cylinder. Fitting a meter-in controller where a meter-out one was is an easy mistake because they look almost identical.

Tell us which you need. If a machine has developed a lurch after somebody changed a fitting, this is the first thing to look at.

Port threads are in the part number

Worth checking in New Zealand, where more than one thread standard is in service.

SMC offers the same body in Rc, G and NPT port threads, and the difference is a character in the part number.

Rc and NPT are both tapered and they are not the same thread. One will start into the other and will not seal properly, which produces a slow leak that gets chased for weeks.

So on a first order for a machine: tell us the thread, or send a photo of the port. On a like-for-like replacement the part number carries it, which is another reason to send the whole string.

Manifolds are configured, and valves come off individually

What failed	What you need
One valve not shifting	That valve, or its coil
Electrical fault on one station	The valve or the interface
Serial unit failed	The EX unit only
Manifold cracked or leaking throughout	The manifold block

An SS5Y or SS5V number describes a built-to-order manifold assembly, so it has to be broken down into its parts to be quoted. A single valve is a much smaller order and it is usually what is needed.

An empty station needs a blanking plate, or the manifold vents and nothing on it works.

Send a photo of the whole manifold, including both ends and the serial unit if there is one. That is faster and more reliable than a parts list.

EX units hold the configuration

An EX serial or fieldbus unit carries the network address and settings. Record them and photograph the unit before removing it, because a replacement arrives at defaults and a correct unit at the wrong address is invisible to the PLC.

As on any networked valve terminal, the valve supply is often separate from the electronics supply. If communications are healthy and nothing moves, check that supply and its fuse before replacing valves.

F.R.L. units are modular

Useful, because it means you rarely replace the whole assembly.

An AC series unit is a filter, a regulator and sometimes a lubricator joined together, and the parts separate.

Failure	Part
Dirty or blocked filter	Element. A consumable
Pressure creeping or unstable	Regulator, or its diaphragm
Cracked bowl	Bowl, and a bowl guard if it did not have one
Drain not draining	Auto drain
Whole unit corroded	The unit

A blocked filter element starves the machine of pressure, which presents as slow, weak actuators and gets diagnosed as worn cylinders. It is the cheapest thing on the list and the first thing to check.

Before ordering

Symptom	Check first
New cylinder fitted, switches dead	The D in the part number. No magnet
Valve will not shift	The manual override, then the coil and its signal
Cylinder lurching or juddering	Meter-in against meter-out speed control
Cylinders failing early across a plant	Whether a lubricator was added and then ran dry
Everything slow and weak	Filter element and pressure at the machine under load
Comms healthy, nothing moves	The separate valve supply and its fuse
Slow leak at a fitting that will not seal	Rc against NPT thread
Switch works slowly, fails in production	A worn reed switch on a fast machine

What to send us

The complete part number. Every character, because several of them are load bearing.

A photo of the item on the machine, which shows mountings, switches and how it is piped.

Whether switches are fitted, and whether your PLC inputs are NPN or PNP.

The port thread, on a first order.

Whether the air is lubricated.

For a manifold, a photo of the whole assembly including the serial unit.

The symptom. On pneumatics the cheap part is usually the answer.

What we can supply

Cylinders. CQ2, CDQ2, CM2, CDM2, CJ2, CDJ2, MB, MDB, C95, MGP, MXS, MY, rotary actuators and grippers, with and without magnets, plus mountings.

Valves and manifolds. SY, SV, VQ, VQC, VF and VZ valves, individual valves off manifolds, blanking plates and EX serial units.

Auto switches. D-M9 solid state and D-A9 reed, in NPN, PNP and two wire, with the cable and connector options.

Air preparation. AC series units, filters, regulators, filter regulators, mist separators, soft start valves, elements, bowls and auto drains.

Fittings and tubing. KQ2 one-touch fittings, tubing, silencers and speed controllers.

Vacuum. Ejectors, suction cups and vacuum switches.

Sensors. Pressure, vacuum and flow switches.

Electric actuators. Actuators, controllers and cables as matched sets.

A sensible SMC spares holding

Item	Why
Auto switches in your PLC's input type	A wear item on fast machines
Filter elements	Consumable, and a blocked one costs you pressure everywhere
One valve per manifold type	Far cheaper than a manifold
Speed controllers and one-touch fittings	Trivial cost, and a machine waits without them
Blanking plates	Prevents a whole manifold going down
Silencers	A blocked one slows everything on that manifold

Common questions

Can you get a part that is not listed on your site?
Usually. The site shows what we hold, not what we can source.

What is the difference between CQ2 and CDQ2?
The D means a magnet in the piston for auto switches. Without it, position switches will not work.

Do auto switches come with the cylinder?
No. They are separate parts, and the type has to suit your PLC inputs.

Should I add an oiler?
Almost certainly not. Modern components are pre-lubricated and added oil washes the factory grease out.

My cylinder judders.
Check the speed controllers. Meter-out is normally correct for a cylinder and meter-in causes lurching.

Do I need a whole manifold?
Rarely. Individual valves and serial units are replaceable.

Do you supply used equipment?
On pneumatics we generally supply new, because seals and coils are wear items. Where a discontinued item only exists as surplus we will say so.

What is the lead time?
Ex stock items ship the next working day within New Zealand. We give you a firm lead time with the quote.

Do you quote in NZD?
Yes, in NZD including GST for New Zealand customers.

Send us your part numbers

All of it, including the letters in the middle. On SMC a single character decides whether the part works on your machine. Quotes in NZD including GST.

Request a quote

Industech is an independent supplier of new, surplus and used industrial automation equipment. We are not an authorised distributor of, approved by, sanctioned by, or affiliated with SMC. SMC and the product series named here are trademarks of SMC Corporation. All trademarks, brand names and part numbers are the property of their respective owners and are used here for identification purposes only.