Vickers Vane Pump Interchange with Denison and Parker

Sometimes, but never as a blind bolt-in. Denison's own interchange sheets pair the T6C with the Vickers 25V, the T6D with the 35V, the T6E with the 45V, and the T6CC, T6DC, T6EC and T6ED doubles with the 2520V through 4535V, and that is the same T6 line Parker builds today; but those sheets also flag differences in pilot depth, shaft length, overall length and, on one pairing, an outlet port size. Cross-reference by matching the mounting flange and pilot, the shaft, every port, displacement at your speed, pressure, rotation and the envelope, and before you do any of it, price a cartridge kit for the Vickers you already have, because that is usually the cheaper and safer fix.

This page shows you how to run that check, what the factory paperwork actually says, and where the traps are. Nothing here is a promise that a given pump fits your machine. It is the list of things that have to match before it can.

Can a Denison or Parker vane pump replace a Vickers V or VQ pump?

Denison thought so, and in 1989 it built a sales packet to help its distributors do exactly that. Vickers saw the same overlap from the other side: its 1995 VMQ marketing kit describes the T6C as the Denison counterpart of the Vickers 25 frame and says the T6 was developed for a higher pressure market than the V and VQ pumps. Parker now owns that line. Its current bulletins are headed "Denison Vane Pumps" and come from Parker Hannifin Manufacturing France in Vierzon, so when someone offers you a "Parker vane pump" to replace a Vickers V, it is a Denison T6 or T7 design.

So the families are close cousins in size, and on the sheets Denison drew up, the flange, bolt pattern, inlet and outlet port sizes and port bolt threads line up on most pairings. What does not line up is the stuff that ruins an install day: a pilot that sits deeper, a spline that is shorter, a pump that is over an inch longer, and one outlet that is a size bigger.

Which Denison pump does Denison pair with each Vickers pump?

These are the pairings printed in SP-549, with the differences Denison itself marked "NOTE" on the sheets. Dimensions are inches, as printed, and each difference is given Denison figure first, then Vickers. The Vickers figures are for standard-pilot V-series pumps of that era.

Vickers pump	Denison pump on the sheet	Flange on both	Differences the sheet shows (Denison vs Vickers)
25V	T6C	4.000 pilot, 2 holes .56 on 5.75 centers	Spline shaft extension 1.62 vs 1.75. Keyed shaft, ports and pilot depth match.
35V	T6D	5.000 pilot, 2 holes .69 on 7.125 centers	Pilot depth .48-.50 vs .37-.38. Body width 5.82 vs 5.55 square. Spline extension 2.19 vs 2.31.
45V	T6E	5.000 pilot, 2 holes .69 on 7.125 centers	Overall length 8.88 vs 8.50. Key length 1.00 vs 1.12. Spline extension 2.19 vs 2.44. Body 6.82 vs 6.25 square.
2520V	T6CC	4.000 pilot, 5.75 centers	Overall length 10.13 vs 9.81. Spline extension 1.62 vs 1.75.
3520V, 3525V	T6DC	5.000 pilot, 7.125 centers	Pilot depth .49 vs .375. Length 11.38 vs 11.57 (3520V) and 11.31 (3525V). Spline extension 2.19 vs 2.31 (the Vickers spline is listed as non-SAE C).
4520V	T6EC	5.000 pilot, 7.125 centers	Length 13.17 vs 11.95. Cover-end outlet 1" on the T6EC vs 3/4" on the 4520V. Key length 1.00 vs 1.12. Spline extension 2.19 vs 2.44.
4525V	T6EC	5.000 pilot, 7.125 centers	Length 13.17 vs 12.80. Key length and spline extension as the 4520V.
4535V	T6ED	5.000 pilot, 7.125 centers	Length 14.21 vs 13.9. Key length 1.00 vs 1.12. Spline extension 2.19 vs 2.44.

Two more things the sheets show if you read the shaft tables closely. The spline tooth count, pitch and pressure angle match on every pairing (13 teeth 16/32 on the 25 frame, 14 teeth 12/24 on the 35 and 45 frames), but the major diameter Denison prints for its spline is smaller than the Vickers figure on every sheet, by about 0.014 to 0.029 inch depending on frame (for example .848-.858 against .872-.873 on the 25 frame). And the 1989 sheets compare against standard-pilot Vickers pumps only. They do not print dimensions for VQ pumps, thru-drive VT or VQT pumps, the 20V single or the 50V.

How do you cross-reference a Vickers vane pump to another brand?

A Vickers, Eaton Vickers or Parker cross reference comes down to the same physical checks, because we have found no current one-to-one interchange from any maker (the V Series catalog 560 is an Eaton document, and it lists no Denison equivalents). Work through it in this order. Stop at the first thing that does not match and decide whether you can live with it.

1. Read the whole Vickers model code. Frame, ring size, pilot letter, shaft code, outlet position, design number, rotation and any special suffix. Our Vickers model number decoder and how to identify a Vickers pump walk through it. If the tag is gone, start with identifying a pump with no tag.
2. Check the mounting flange and pilot. Pilot diameter, pilot depth, bolt hole size and bolt centers. In the current Vickers V catalog, a code with no pilot letter is the Vickers standard pilot, "S" is SAE per ISO 3019/1 (SAE J744) and "M" is metric. Special suffix 167 on a 25V means a 2-bolt flange with a 5.00" pilot instead of the usual 4.00". Measure the adapter's pilot bore depth too: a deeper pilot, like the T6D's, has to have somewhere to go.
3. Check the shaft. Keyed or splined, diameter, key size and key length, spline teeth, pitch and major diameter, and how far the shaft sticks out. A shorter spline means less engagement in the coupling. Parker wants the female spline to a Class 1 flat root side fit per SAE J498b, hardened and lubricated.
4. Check every port. Size, four-bolt flange thread and depth, and position. Vickers states outlet position viewed from the cover end; Denison uses its own porting code. Match the physical position on the bench, not the letter or number.
5. Match displacement at your speed, not the code number. See the next section.
6. Match pressure and speed for your actual duty. Use the continuous rating for the exact ring or cam size, and the fluid you run.
7. Match rotation. Both makers state rotation viewed from the shaft end: R is clockwise, L is counterclockwise. See how to tell and change pump rotation.
8. Doubles: match which section is which. On a Vickers double the large ring is at the shaft end. Make sure the new pump's P1 and P2 feed the same circuits with the same flows.
9. Check the inlet, drain and envelope. Inlet location and size, overall length, body width, foot brackets and anything bolted to the cover. More on the inlet below.

How do Vickers ring sizes compare with Denison cam sizes?

This is where most cross-references go wrong. On a Vickers V pump the ring number is the rated flow in US gpm at 1,200 rpm and 100 psi, so a 25V21 is a 21 gpm ring. The Denison number is a cam size, and the same number does not mean the same displacement. A 25V17 is 3.39 cu in/rev; a T6C 017 is 3.56. Compare cubic inches per revolution, from each maker's catalog:

Vickers ring	Vickers in³/rev	Nearest Denison cam (in³/rev)
25V12	2.47	T6C 012 (2.26) or 014 (2.81)
25V14	2.78	T6C 014 (2.81)
25V17	3.39	T6C 017 (3.56)
25V21	4.13	T6C 020 (3.89) or 022 (4.29)
35V25	4.94	T6D 024 (4.85)
35V30	5.91	T6D 031 (6.00)
35V35	6.83	T6D 035 (6.77)
35V38	7.37	T6D 038 (7.34)
45V42	8.41	T6E 042 (8.07) or 045 (8.69)
45V50	9.85	T6E 050 (9.67)
45V60	11.75	T6E 062 (12.00)

Then work out flow at your motor speed: gpm = in³/rev × rpm ÷ 231. At 1,800 rpm a 25V21 is about 32.2 gpm theoretical. A T6C 020 gives about 30.3 and a 022 about 33.4. Neither is the same pump. Cylinders run a little slower or a little faster, and if the circuit was sized tight, that matters. Our hydraulic calculator does the math.

How do the published ratings compare?

Comparable published specs only. This table is not an interchange; verify mounting and ports with the sheet above or the catalogs. Vickers figures are from the V Series catalog 560 (November 2011); Denison figures are from the industrial vane pump catalog 2-AM-VP002-BB (February 2000), mineral oil.

Frame	Displacement	Max continuous pressure	Speed range
Vickers 20V	0.43-2.78 in³ (7-45 cm³)	2,000 to 3,000 psi depending on ring	600-1,800 rpm
Vickers 25V	2.0-4.1 in³ (33-67 cm³)	2,500 psi	600-1,800 rpm
Vickers 35V	4.9-7.4 in³ (81-121 cm³)	2,500 psi	600-1,800 rpm
Vickers 45V	8.4-11.75 in³ (138-193 cm³)	2,500 psi	600-1,800 rpm
Denison T7B / T7BS	0.35-3.05 in³	4,305 psi (B02-B10), 4,000 (B12), 3,480 (B15)	600-3,600 rpm (to B10), 600-3,000 above
Denison T6C	0.66-6.10 in³	3,500 psi (003-025), 2,500 (028, 031)	600-2,800 rpm (to 025), 600-2,500 above
Denison T6D	2.90-11.63 in³	3,045 psi (014-045), 2,320 (050), 1,160 (061)	600-2,500, 2,200 or 1,800 rpm by size
Denison T6E	8.07-16.41 in³	3,045 psi (042-072), 1,090 (085)	600-2,200 rpm, 2,000 on 085

For the mobile VQ pumps, Denison's 1989 sheets list the Vickers VQ at 3,000 psi continuous on the 25, 35 and 45 frames, against 2,500 psi for the industrial V. We do not have a Vickers VQ catalog page to confirm that, so check the VQ sheet for your unit. Also note that V and VQ are not one pump with two names: they take different seal kits, and Vickers' own kit reference (I-4000-S) lists them separately frame by frame.

Direction matters

Going from Vickers to Denison, the Denison ratings are equal or higher, so pressure and speed are rarely the problem; fit is. Going the other way is where people get hurt. A Vickers 25V, 35V or 45V is rated 2,500 psi continuous. If the Denison you are replacing was set at 3,000 psi or more, a V-series pump is not rated for that job, no matter how well it bolts up.

What about the inlet, case drain and minimum pressure?

• No case drain on the V series. Vickers says the V pump drains internally to its inlet and limits inlet pressure to 20 psi (1.4 bar).
• Denison shaft seal limit. Parker's T7/T67/T6 instructions limit standard shaft seals to 10 psi gauge (0.7 bar), with some seals allowing 100 psi. If your inlet is flooded from a tall tank or boosted, check the seal before you swap.
• Minimum outlet pressure. Denison's 2000 catalog sets 150 psi as the minimum outlet pressure for its industrial vane pumps, and Parker's later bulletin recommends at least 22 psi (1.5 bar) between inlet and outlet. If your pump idles unloaded to tank, ask Parker which applies. Vickers warns never to run its V pump with outlet pressure below inlet pressure.
• Fluid. Both makers derate for water glycol, emulsions and synthetics. Check both catalogs for your fluid, not just the mineral oil line.

Is a cartridge kit a better fix than switching brands?

Most of the time, yes, and that is the advice we give across the counter. A Vickers V pump is built so the cartridge (ring, rotor, vanes and support plates) is independent of the drive shaft. Vickers' own catalog makes the point that you can service the pump or even change its flow without taking it off its mounting. A new cartridge and seal kit gives you a pumping element at new-pump performance and leaves the flange, shaft, coupling, ports, hoses and guards exactly as they were. Every item on the checklist above is already right.

A brand swap puts every one of those items back in play. Even when it goes well, it often means a new coupling half, new port flanges, a hose or two and a guard that no longer clears. Our Vickers vane pump cartridge kit rebuild guide covers picking the right kit by code and putting it in.

Switching brands earns its keep when:

• The body or cover is scored, cracked or worn past the factory limits, so a cartridge has nothing good to sit in.
• The job needs more pressure or speed than the Vickers V is rated for.
• The plant already runs T6 pumps and wants one set of spares.

One more thing: cartridges do not cross between brands. Vickers lists its cartridge kits against Vickers frames in I-4000-S, and Denison lists its own in its service information. Nothing we have on file cross-lists a Vickers cartridge for a Denison body or the reverse.

Factory service data for the cartridge route: Vickers 25V, 35V, 45V, 2520V and 45VQ sheets. For the Denison side: T6C, T6D and T6E service information.

Where do I find parts and catalogs for each family?

• Vickers: Vickers vane pumps, the 25V/25VQ/35VQ catalog, 35V catalog, 45V catalog, 45VQ catalog, 2520V/2520VQ doubles, 3520V/3525V doubles, 4520VQ-4545VQ doubles, and Vickers vane pump seal kits.
• Denison and Parker: Denison vane pumps, the Denison T-series catalog, the Denison vane pump model code decoder, and parts for the T6C, T6D and T6E.

Frequently asked questions

Related reading

• Vickers vane pump cartridge kit rebuild guide
• How to tell and change hydraulic pump rotation
• How to read a Vickers pump model number
• Denison vane pump model code decoder
• Denison pump guide: Gold Cup, T6 and T7
• Vickers V10 vs V20 vane pumps
• Hydraulic pump start-up procedure
• What hydraulic pump repair actually costs