Dibblee

ZEP Style B Zinc Fairwater Slab Anode — Circular

Size Style B — 2 in diameter — 0.35 kg (0.79 lb) minimum Style B — 3 in diameter — 0.81 kg (1.78 lb) minimum Style B — 4 in diameter — 1.45 kg (3.19 lb) minimum Style B — 5 in diameter — 2.2 kg (4.9 lb) minimum Style B — 6 in diameter — 3.3 kg (7.2 lb) minimum Style B — 9 in diameter — 7.3 kg (16 lb) minimum Style B — 11 in diameter — 10.9 kg (24 lb) minimum

Quoted on request. Price depends on the steel market and freight to your port. Tell us your port and specification and we will quote it delivered.

ZEP Style B Zinc Fairwater Slab Anode — Circular

The circular fairwater slab, 1 in thick, in seven diameters from 2 in to 11 in. Style B of the ZEP family.

Zinc sacrificial anode to MIL-DTL-18001L, type ZEP-B — fairwater slab, circular, pipe core. Supplied in 7 sizes. Quoted on request.

Sizes and weights

Type	Size	Minimum weight	Spec figure
ZEP-B-2	Style B — 2 in diameter — 0.35 kg (0.79 lb) minimum	0.35 kg (0.79 lb)	Fig 13
ZEP-B-3	Style B — 3 in diameter — 0.81 kg (1.78 lb) minimum	0.81 kg (1.78 lb)	Fig 14
ZEP-B-4	Style B — 4 in diameter — 1.45 kg (3.19 lb) minimum	1.45 kg (3.19 lb)	Fig 15
ZEP-B-5	Style B — 5 in diameter — 2.2 kg (4.9 lb) minimum	2.2 kg (4.9 lb)	Fig 16
ZEP-B-6	Style B — 6 in diameter — 3.3 kg (7.2 lb) minimum	3.3 kg (7.2 lb)	Fig 17
ZEP-B-9	Style B — 9 in diameter — 7.3 kg (16 lb) minimum	7.3 kg (16 lb)	Fig 18
ZEP-B-11	Style B — 11 in diameter — 10.9 kg (24 lb) minimum	10.9 kg (24 lb)	Fig 19

These are the minimum weights set by MIL-DTL-18001L, not the nominal. A ZHS-23 carries a 21.5 lb minimum, not 23 lb — the number in the designation is nominal.

Full dimensions, in inches and millimetres together, are on the specification drawing in the images above — that drawing is the only place those dimensions exist in both units.

Alloy and water

MIL-DTL-18001L is a zinc specification, supplied to ASTM B418 Type I — the alloyed seawater grade whose composition is written to meet MIL-A-18001K. That is why every supplier's datasheet claims to "meet or exceed military specification".

For fresh water zinc is the wrong alloy: use magnesium to ASTM B843, or zinc to ASTM B418 Type II, the high-purity grade for fresh and buried service. We cast to either — say which water it is going into and we will quote the right one.

What to put on your purchase order

Zinc anodes fail by passivating: they skin over and stop producing current while still looking perfectly serviceable. Iron contamination is the usual cause, which is exactly what ASTM B418 caps at 0.005%. Specify "to ASTM B418 Type I, mill certificate with each lot" and you have something to test against.

Sizing

The specification sets what the anode is, not how much of it you need. That comes from DNV-RP-B401 for ships and offshore structures and ABYC E-2 for boats. Whatever the calculation says, replace at about 50% wasted — output falls away as surface area is lost, so the last half protects far less than the first.

Reading the type code

These designations come from the military specification, not from any manufacturer, which is why the same letters appear across every brand and why an old anode can nearly always be identified. Three letters: metal, then shape, then core. Z is zinc; H hull slab, S submarine slab, T teardrop, E fairwater slab, R rod, B bar, D disc, M mooring chain; then S steel strap, B brass straps, C core strap, P pipe core, M interlocking core, N no core.