PulseGuard Pulsation Dampeners

Fluid Flow Control Animations
PulseGuard Pulsation Dampeners
Contact PulseGuard

PulseGuard Pulsation Dampeners PDF

Does anyone know what anyone else means by
A Polished Smooth Clean CIP Flushable Crevice?

In the context of liquids handling equipment that is for the following industries, (in probable descending order of cleanliness): Electronics, Biotech, Drug, Pharmaceutical, Milk Products, Juices, General Foods, Beverages, Coloring Additives, etc. – AND– In the absence of a copy of your different definitions, we will apply the following meanings and abbreviations to the following terms when such words are communicated to us, and they will have these meanings in our communication to you. These form part of the definitions in our ISO 9001 type Quality System in Part 1 and are applied to Part 2 procedures used in the design selection verification and production of Pulse Preventors for all of the referenced applications. The effort here is at “street” non-tech broadly understandable language UNTIL you care to make different definitions, which we look forward to receiving.


Norms for the Electronics component industry & some Biological Engineering applications:

Sometimes referred to as SEMATECH (Semi Conductor Assoc. Tech. Organization) TEXSPEC (now defunct) of Austin, Texas draft materials. Generally indicates a flushant resistivity test down to 18 megohms. A starting point for materials may be the use of Carpenter Technologies 316L “SCQ” (Semi Conductor Quality), VIM (Vacuum Induction Melt) plus VAR (Vacuum Arc Remelt – this is max surface of area metal “droplet” in air technology) giving reduced levels of hydrogen (50 ppm) and Sulfur (0.005%). For machining ability a sulfur of 0.015 may be thought desirable so the AOD (Argon Oxygen Decarburized) plus VAR process can be specified. -OR- ESR (Electro Slag Remelt) process may be relevant in order to NOT lower the nitrogen level in molybdenum alloyed material but to lower some diatomics, so the Allegheny Ludlum Company Grade 6XN may also be suitable. (The danger here is higher hydrogen from moisture in the slag.) Finishes will be by electro-polish / auto-passivated to 6-8 microinch CLA. The choice of material will largely depend on the sulfur level that you state to be tolerable. In the absence of such determination only low pressure fluoroplastic component equipment can be offered.

Sometimes referred as “clinically clean”. Designed to have minimal entrained volume (flow residence time), 90 degree shut off at seal points to be “clinically clean”, by preventing any ingress / entrapment, “CIP”, from sterilizable materials and using stainless steel that is 316L grade but with a 0.017 max sulfur content. (See also German DIN steel spec# 11850 and referenced DIN 17455 & 6.) “FW” with 120 grit, then “PHN” to 16-32 microinch CLA, then “BPL” to 4-8 microinch CLA, the dirt loading from which is then removed by “EPL” to 8-12 microinch CLA (passivation also occurs by virtue of the acid used in “EPL”). Note: Valex has purer standards for the Mega Chip industry.

“HG” – Hygienic
Sometimes referred to as “sterile”. Designed to have 90 degree shut off at seal points to prevent the ingress / retention of microbic or particulate traces, “CIP”, from “sterilizable” materials and finished “smooth”.


A norm for Drug & Pharmaceutical system “clean” components
(excluding seal housing which are generally sterilized by immersion):

Liquid contact surfaces that are free from any indentation that (when greater than 0.0005 inches in their longest dimension) have a depth of more than 1.5 times the largest dimension of the opening into that indentation then finished “smooth”. Note: This specifically prohibits the use of our bellow membranes. Bellows are described as a series of maximized crevices, or the use of our tapered membrane in parallel housing, which is, by virtue of the tapering gap, a maximum crevice.


Norms for General Foods equipment
(which may run several batches between strip down for sterilization by submersion of its liquid contact parts):

Clean between batches by near “plug flow” displacement. Designed to have multiple connections that are so positioned to enter and leave the process liquid chamber causing there to be a turbulent scouring action when 10 ft/sec velocity of cleaning fluid is flowed through the liquid chamber, having an average 40 microinch CLA finish (definitely not buff polished).

The life of liquid contact parts which are not more than slightly reduced by a 30 minute contact with deionized water at 100 degree C and / or a strong caustic or chlorine germicide or bactericide at 60 degree C. (Materials compatibility of such substance to be disclosed by user at time of the bid, engineering verification by equipment supplier.)


A norm for liquids (like some Beverages) which do not “sour” or make biological growth” readily:

Designed to provide multiple connections for continuous flow through of the liquid, with 20 to 30 microinch CLA liquid contact surfaces finish.


A norm for liquids such as Coloring Additives which may change between one product run and the next for the purpose of changing COLOR, SCENT, VISCOSITY or FLAVOR (or the like, but which are not made useless by minute traces from the previous run). Examples: Spirit Lotions (aftershave), Spirit Drinks (which are antiseptic in nature).

Designed for one single process connection per pump head and also one connection for periodic use by a flush system that is attached to it, having a 30-60 microinch CLA. Note: The least stringent of these applications may even tolerate the use of pipe as opposed to tube and also be able to use pipe threads and / or ANSI B16.5/DIN 2501 flanges. Then the Pulse Preventor surface can be 125 microinch CLA.


A norm for liquids which carry PARTICULATE and which have periodic use:

Designed for easy disconnection from the system normally by the use of a quick clamp fitting and which when depressurized may be cleaned by the insertion of a jet cleaning wand or “lance”. Liquid contact surfaces are 200 microinch CLA.


A norm for liquids which, in the absence of a chromium oxide layer will cause CORROSION PITTING of 316
stainless steel or which will be unacceptably contaminated by sulfur or other trace element out-gassing.

Generally starting from bright annealed stainless, treated by a caustic hot wash followed by acetic acid then 20% nitric acid.



Rotary abrasion from internal diameter by a flap wheel on the liquid contact surfaces to reduce the height of longitudinal striations remaining from tube drawing or previous mechanical operations, to produce a 180 grit / 85 microinch CLA finish, generally as a pre-work for past honing.

Height of radial striations in a bore reduced using high velocity erosion with an abrasive 320 paste or putty. Generally to produce a 10-32 microinch CLA finish before buffing and / or electro-polishing.

A 4 to 16 microinch CLA finish (also known as 500 grit).

The height of roughness reduced by the use of abrasive stones rotated while stroked along the axis of a straight and parallel bore. Not generally to better than a 6-8 microinch CLA finish. Used for sliding seal applications.

The changing of surface roughness by the electrolitic removal of protrusions using a copper electrode specifically shaped to suit the component shape and within an acid electrolite. A 35% reduction in the height of a prior existing 180 grit finish can be expected. An improvement of not more than 50% can be attained under best conditions. In the event that the surface was first buff polished to 2-4 microinch CLA mirror finish then the removal of the furred over edges and the dirt loaded beneath them will cause an increase in roughness to about 8-12 microinch CLA. Passivation will also occur.

Subjected to the furring over of the peaks of roughness over the valleys in order to produce a shiny surface appearance. The entrapment / loading of the surface with buffing material in the space between the furred over or pushed over edges and the valleys beneath them makes such surfaces impossible to clean and is accordingly quite unsuitable for all applications. Only offered where the specifier accepts any and all consequences in writing before bid.

3A is the name of a committee with special interests in the dairy industry. The 3A standards contain a polishing requirement. This polishing requirement is enforced by a visual comparison against a piece carried by the inspector. The acceptability of such inspected surface appearances by individual local inspectors varies; as does the amount (if any) of communication between the 3A people and local and state agency authorities with responsibility for cleanliness enforcement. The standards implied by this designation use the grit finish numbers for which there are no calibrated instrument tests and stated ASTM material specifications which can not be used in the construction of pressure products which require SA material certificates to be in accordance with pressure containing product codes. Accordingly, within the strictures of our ISO 9001 type Quality System, we are unable to designate any item made to this standard as suitable for any clean service. Any attempts to make items in accordance with this standard are at customer’s own risk. (See the effects of polish at “BPL” above.)



A “/” or “–” followed by any of the following abbreviations shall only mean that the particular type of fitting will be attached. There is no implication by the use of such fittings that any specific standard of Pulse Preventor is being supplied, nor is there any implication that a particular surface standard has been met simply by virtue of the fitting designation alone. In approx. descending order of cost:

“Clean” Connection Name



Standard Surface

Type of Joint

Recess Joint Type BS 1846



8 microinch CLA

Nut + O ring

International Dairy Fed. BS 4825 & ISO 2583



16 microinch CLA

Nut + O ring

Deutsches Institute Norm 11850/1

Germany , Spain


32 microinch CLA

Nut + O ring

Danish Standard Union

Denmark , Holland


48 microinch CLA

Nut + O ring

Swedish Military Spec. Union

France , Scandinavia


64 microinch CLA

Nut + O ring

In-Line Cleaning – high pressure fitting

Dairy Pipe Lines Ltd.


32 microinch CLA

Nut + O ring

Separa-Sys / FMC-R.O.

California Hose & Fitting Co.


48 microinch CLA

Nut + O ring

Stainless Product Inc

Valex – CA


3A +

Quick Clamp

Tri-Clover / “TriClamp

Alfa Laval



Quick Clamp





Quick Clamp


SanPro K” Andover , NJ


Pure but >100 microinch CLA

Quick Clamp

A means of attaching two items with a segmented internally grooved ring which resists the parting force of two lips that are engaged in the groove. The segment ends are generally held to one another with a minimum number of bolts that have smooth threads. The purpose may be to provide a closure that can be opened quickly in order to clean before the liquid solidifies or sets.



Visual and fingernail tactile comparisons are near impossible to qualify objectively, the use of terms like #4 finish or 220 grit are not acceptable. Believable surface roughness measurement “Profile-ometer” tools are suggested such as “Tally-Surf”, “Federal Pocket Surf” and “Hommel Val-Met” which will give you microinch Center Line Average (CLA) figures. CLA is also known as roughness average (Ra), particularly when using metric surface finish expressions. RMS, root mean squared (Rq), is a term some like to use a lot. Useful figures are also had from the Rmax and Rz (Rt is the metric equivalent) functions. Rz (Rt) may generally be expected to be 4 to 12 times the microinch CLA value (4 to 12 Ra).



Also Micro Chip & Space: An elegant method of surface profile determination, that may be necessary with equipment for the Electronics industry, is to put a spot of acetone on the surface and place a wafer of acetate on the spot. This is then dissolved and resets with a fingerprint of the surface on the contact face. The reset wafer has its back flash gold plated and is placed on a glass, an electron microscope 2000:1 magnification is then scanned into a computer for viewing and analysis to determine the profile. Electro-polishing suitability for electronic industry applications can be determined by the “Auger” (with a French pronunciation) test and the ESCA test. One determines the depth profile and the Angstroms thickness of 30-40 of the chrome oxide layer and the other relates the oxidation status of chrome to iron with preferably a 2:1 ratio. These tests are related to the possibility of “out-gassing”, (which may be the emission of sulfur, carbon molecules, etc.).

Items that undergo the above degree of stringency will probably be washed with hot deionized water, have an 18 megohm test taken on the flushant, dried with hot 99.999% pure (approx. 1ppm O2, 0.2ppm HCs, 1ppm H20) microchip grade nitrogen and be sealed. This all being done in a white / clean room of course. Some customers may use the words “Super Pure” or the manufacturer’s name “Valex” to alert you.

A small quantity of a given item for “belly wash wine” on the one hand and the same items for a micro chip or space application may COST 100 TIMES the other. All other application fall in between so PLEASE BE SPECIFIC.



PulseGuard Pulsation Dampeners
Phone: 910-270-2737 • Toll Free: 1-888-DAMPERS (326-7377) • Fax: 910-270-2739
295 Sloop Point Loop Road, Hampstead NC, 28443 USA • Contact Us

Fluid Flow Control Pulsation Dampeners