Frick Screw Compressor Foundations Installation guide

Brand: Frick

Model: Screw Compressor Foundations

Type: Installation guide

SCREW COMPRESSOR

FOUNDATIONS

Form 070.210-IB (JUN 2018)

INSTALLATION BULLETIN

File: SERVICE MANUAL - Section 70

Replaces: 070.210-IB (APR 2014)

Dist: 3, 3a, 3b, 3c

Please check www.johnsoncontrols.com/frick for the latest version of this publication.

SCREW COMPRESSOR

FOUNDATIONS

070.210-IB (JUN 2018)

Page 2

Figure 1. Preparation and Anchoring

HOUSEKEEPING

PAD

CONCRETE

FLOOR

6in.

CHIP CONCRETE SURFACE

TO EXPOSE CHIPPED AND

BROKEN AGGREGATE

WOODEN FORM

EPOXY GROUT POURED ½ ABOVE

BOTTOM OF COMPRESSOR BASE

WRAP ANCHOR BOLT WITH TAPE

TO ALLOW IT TO STRETCH

55% of L

45% of L

COMPRESSOR

PACKAGE

BASE

JACKING SCREW WITH HEAVY

COATING OF NON-MELT GREASE

ROUND METAL

LANDING PAD

GLUED TO

CONCRETE

WITH EPOXY

1in.

MINIMUM

THICKNESS

NOTICE

Drawing NOT to scale!

SCREW COMPRESSOR FOUNDATIONS

GENERAL

The rst requirement of the compressor foundation is that it

must be able to support the weight of the compressor pack-

age including coolers, oil, and refrigerant charge.

Screw compressors are manufactured to extremely low levels

of rotating imbalance and because of this do not generally

require the massive foundations used with older reciprocating

compressors or large engines. However, it must be recog-

nized that screw compressors are capable of converting large

quantities of shaft power into gas compression in a relatively

small space and that the installation of any high-speed,

high-power equipment should not be approached casually.

The predominant frequency of vibration produced in a screw

compressor package is at lobe-passing frequency. This is

normally 200 to 600 Hertz, depending on drive speed and

compressor model. Much less mass is required to effectively

dampen these relatively high-frequency vibrations compared

to low-frequency vibrations found in lower speed equipment.

Firmly anchoring the compressor package to a suitable foun-

dation by proper application of grout and elimination of piping

stress imposed on the compressor is the best insurance for

a trouble-free installation. While a compressor may operate

successfully on a poor foundation it is certain that vibration

levels on the compressor package, and noise levels emanat-

ing from the compressor package will be higher if it is not

rmly tied to the foundation mass. It is not unusual to see

a ten-fold increase in vibration level measured on a screw

compressor package when comparing a properly mounted

package to one that is not tied to the foundation mass.

Use only the certied general arrangement drawings from

Frick® to determine the mounting foot locations and to al-

low for recommended clearances around the unit for ease

of operation and servicing. Foundations must be in compli-

ance with local building codes and materials should be of

industrial quality.

PREFERRED INSTALLATION METHOD -

CONCRETE FOUNDATIONS

Preparation and Anchoring

As seen in Figure 1, the oor should be a minimum of 6” of

reinforced concrete. Anchor bolts are required to rmly tie

the unit to the oor. If the oor is new, it is recommended

that “L”, “J” or expanding type anchor bolts be installed at

the time the concrete is being poured, at the correct locations

for the foot anchor holes on the package. You do not need a

sleeve around the bolt. Wrap the bolt with tape so the grout

SCREW COMPRESSOR

FOUNDATIONS

070.210-IB (JUN 2018)

Page 3

and concrete don’t stick to the bolt. The bolt needs to be

allowed to free-stretch over a length of 10 times the bolt’s

diameter. This is just a rough estimation tool. Normally you

can take your anchor bolts and cover 45% with tape. If you

do have a sleeve, either wrap it with tape before you ll it

with grout or ll it with expanding foam that comes in a can.

For compressor packages being installed on existing concrete

ooring, there are two recommended anchoring options:

1. High quality expanding anchors. These anchors are wedge

type and must be designed to withstand vibratory load-

ing. An example of this type is the Simpson Strong-Tie®

Strong Bolt Wedge Anchors

2. All threaded rod anchor. This option must be combined

with an epoxy type system approved for anchoring (e.g.

HILTI® HIT-HY 200) and shall follow the manufacturer’s

recommendations.

The material types used should be stainless steel (grades

304 or 316 are common) or a carbon steel material with a

non-corrosive coating (e.g. zinc plated) to prevent corrosion

of the exposed portion of the anchor. The diameter should

be 1/8” or 1/4” smaller than the hole in the stand assembly.

The concrete must meet the minimum strength as specied

by the manufacturer of the anchor.

The anchor bolts must be of sufcient length to extend from

the base through the housekeeping pads, through the steel

frame of the package, allowing 1 inch for grout installation

and 1.5 bolt diameters for nut installation. In addition, the

anchor bolt must maintain a minimum insertion depth into

the base oor as specied by the anchor manufacturer. (See

Figure 2)

Figure 2. Anchoring and Grouting

HOUSEKEEPING PADS

UNDER FEET ONLY

HOUSEKEEPING PAD

UNDER ENTIRE UNIT

HOUSEKEEPING PADS

UNDER FEET ONLY

HOUSEKEEPING PAD

UNDER ENTIRE UNIT

Figure 3. Housekeeping Pads

STEEL COMPRESSOR BASE

EXPANDING ANCHORS

FOR EXISTING FLOORS

EPOXY GROUT

L OR J ANCHORS

FOR NEW FLOORS

L OR J ANCHORS

FOR NEW FLOORS

1GROUT

HOUSEKEEPING

PAD

MINIMUM

CONCRETE

FLOOR

JACKING SCREW REMOVED

AND HOLE FILLED

WITH SILICONE

SCREW COMPRESSOR

FOUNDATIONS

070.210-IB (JUN 2018)

Page 4

Housekeeping pads (See Figure 3) are often utilized but are

not required. Standard packages are designed assuming a

6” high housekeeping pad to align the quantum panel at a

reasonable viewing angle and providing service/maintenance

access to the lower section of the package where drains and

valves are located. Structurally stable housekeeping pads

of slightly different thicknesses may be used at customer's

discretion.

Allow sufcient time for the concrete foundation to fully

cure. It must have sufcient strength, have stopped shrink-

ing, and contain very little water in order to be able to grout

on top of it.

The unit can now be rigged into proper position. Use proper

lifting points as dened in the Installation, Operation, and

Maintenance manual. Please note that some units, particu-

larly with installed oil coolers or economizer vessels, can be

top-heavy. Exercise caution to avoid tipping the unit.

Leveling and Grouting

The unit should be leveled in both directions, primarily for

aesthetics and square piping connections. Set and align the

compressor on top of the concrete giving yourself at least

1” clearance for the grout.

Use a Jacking Screw through the compressor mounting plate

to adjust the height of the compressor and align it. There

needs to be a jacking screw in each corner of the mounting

feet. The entire weight of the compressor is to be transferred

through the epoxy grout, not on steel leveling shims. The

threads of the Jacking Screw should be coated with a non-

melt grease to prevent them from sticking to the epoxy. The

Jacking Screw should not be on concrete. Rather, it should

rest on a round metal landing plate that has been epoxied to

the surface of the concrete. After the grout has cured, take

the screw out and ll the hole with Silicone sealant.

Mix a sufcient quantity of grout as directed. A nonshrink

epoxy grout must be used. The grout must be worked under

all areas of the base with no voids. If the grout is allowed to

settle with a slight outward slope, oil and water will be able

to run off the base.

Fill the form up until the grout is about ½” above the bottom

of the compressor mounting pad. It takes 24 hours at 72°F

for most grouts to cure. The grout shall have a minimum

compression strength of 5000 psi within 24 hours after ap-

plication. After the grout has cured, remove the forms and

the jacking screws, and tighten the nuts on the anchor bolts.

The use of an epoxy based, non-shrinking grout is required.

Follow the manufacturer’s recommendations for mixing,

working time, grout placement, nishing, and curing.

Installation on a Steel Base

When a Frick screw compressor package is to be installed

in a customer-packaged system, it is common to mount the

compressor unit directly onto a steel system base. In these

cases the design of the system base and the mounting of the

system base to the customer’s foundation are very important

factors in minimizing vibration. The following guidelines are

provided as an aid in properly designing a system base.

1. Use I-beams in the skid where the screw compressor will

be attached to the system base. The I-beams should run

parallel to the package feet and support the feet for their

full length.

2. The compressor unit feet should be continously welded

to the system base at all points of contact.

3. The customer’s foundation for the system base should

fully support the system base under all areas, but most

certainly under the I-beams that support the compressor

package.

4. The system base should be leveled and grouted to the

customers foundation with the same precautions as noted

above for a single compressor unit mounted directly on

concrete.

5. The system base should be rmly bolted to the customers

foundation with suitable anchor bolts.

6. Whenever possible, the entire system base should be

designed without piping runs inside of the I-beam base.

Figure 4. Skid Installation - Anchoring on Weight-bearing Beams

SCREW COMPRESSOR

FOUNDATIONS

070.210-IB (JUN 2018)

Page 5

7. Whenever possible the system base should be completely

lled with concrete as an added precaution to prevent

vibration. The concrete must be allowed to fully cure

without the unit operating so it will maintain contact with

the steel structure.

8. To attach a compressor base to a foundation, use anchor

bolts at the primary points on the skid where component

weight bears on the main beams, not between main load

bearing locations. (Fig. 4) Additional anchor points can

be used to supplement attachment, as long as the load-

bearing points are included as primary anchor locations.

Installation on Upper Floors of Buildings

When screw compressors are to be mounted on upper oors

of buildings, extra precautions should be taken to prevent

normal package vibration from being transferred to the

building structure where it might cause unacceptable noise

or vibration. It is important that no structural resonance of

the building is near the primary frequencies generated by

the screw compressor, (lobe passing frequency and its har-

monics). If this is the case the vibration levels of the screw

compressor unit can be greatly magnied by the structure

of the building.

When a compressor is to be mounted directly on a steel

building structure, it is essential to use rubber or spring isola-

tors, or a combination of both, to prevent the transmission

of compressor vibration directly to the structure. The choice

of the proper type of isolation is important. Neoprene rubber

isolation pads (VMC Shear-Flex for example) have been used

effectively in many applications.

Pad type and surface area (square inches) are based on to-

tal weight and deection of the pad. In applications where

very low levels of transmitted vibration are required, spring

isolators may be necessary. It is best to employ a vibration

expert in the design of a proper mounting arrangement,

taking account of spring, mass, and damping requirements

to meet the customer’s desired end result.

If a screw compressor package is fully isolated from the

foundation, and not tied to any structural mass, the vibration

and noise levels on the screw compressor package will likely

be higher than typically encountered in the more normal

concrete base installations because the vibrating components

are not tied to any foundation mass.

The mounting and support of suction and discharge lines is

also very important in situations with the compressor iso-

lated from the structure. Even with very effective isolation

of the compressor feet to the building, any piping that is tied

directly to the structure can also transmit noise and negate

the advantages of isolation. Rubber or spring pipe supports

are generally required to avoid exciting the building structure

at any pipe supports close to the compressor package.

All metal contact paths from an isolated package to the

foundation must be broken. For example, metal conduit from

skid to oor should not be used.

PIPING STRESS

In any screw compressor installation, once the package is

installed, properly grouted, and anchored, it is important

that the piping bolted to the screw compressor not impose

excessive forces or moments on the compressor. Suction and

discharge lines should be supported in pipe hangers so that

the lines won’t move if disconnected from the compressor.

The Table on the back cover gives maximum allowable ange

loadings for various size compressors.

GAS OR DIESEL ENGINE DRIVEN PACKAGES

Screw compressors may be driven with large stationary

engine or turbine drives in order to reduce electrical de-

mand or reduce electric energy consumption. Some special

considerations should be given to foundations for engine

drives in order to avoid vibration problems on these skids.

1. The engine or turbine manufacturer will normally give

foundation mass requirements for the driver. These

are normally much heavier than would be used with an

electric motor driven screw compressor. A typical, large

(500 HP), gas engine drive may require 4 ft of concrete

foundation thickness under the engine in order to absorb

the normal vibration associated with the engine.

When the engine is skid mounted with a screw compres-

sor, it is not acceptable to spread the recommended

foundation mass requirement for the engine under the

entire screw compressor driveline. In other words, 1 ft

thick concrete under a 20 ft long package is not equivalent

to 4 ft thick concrete under the 5 ft length of the engine.

The foundation requirement for the engine must be under

the engine. Too much foundation will never hurt, but as

a minimum the engine must be over and rmly anchored

to its required foundation mass.

NOTICE

A licensed architect should be consulted to determine

the proper foundation requirements for any large engine

or turbine drive.

2. A torsional vibration analysis should always be performed

by a capable party before nal component selection

in order to avoid torsional resonance in any engine or

turbine-driven screw compressor. This analysis will de-

termine the recommended coupling inertia and stiffness

to tune the system torsional natural frequency, and its

harmonics, away from the operating speed or speeds.

Once the proper couplings have been specied, no sub-

stitutions should be made unless the substitute coupling

type is again checked by a new torsional analysis.

3. The attachment of an engine or turbine base to a screw

compressor must be of sufcient rigidity to maintain

coupling alignment specications at the compressor. For

Frick compressors this is normally within .004 inch TIR

radial and axial.

It is recommended that the driver and compressor be on

the same structural steel skid or that separate skids for

the driver and compressor be bolted together through

dowelled connection pads.

SCREW COMPRESSOR

FOUNDATIONS

070.210-IB (JUN 2018)

Page 6

4. Engine drive compressor packages can be quite heavy and

the weight will normally be concentrated on the engine

end of the skid. Extra precaution should be exercised in

lifting and rigging of large heavy skids. It is likely that the

greatest stress on the skid will occur during rigging and

lifting into position.

Improper lifts can permanently distort a skid and be very

expensive to x. Before rigging and lifting a heavy skid,

make sure adequate lifting points are being properly

supported.

5. As an option on engine driven screw compressors, the

system designer should always consider the cost of a

gear driven speed increaser between the engine and

compressor compared to a direct-driven larger compres-

sor to produce the same displacement.

The larger direct drive compressor will have a consider-

ably simpler drive and coupling arrangement and simpler

alignment procedures. This will normally produce lower

noise and vibration levels and may be more cost effective

as well.

HIGH POWER APPLICATIONS

Screw compressors are very exible in their ability to com-

press a wide variety of gases over a wide range of pressures.

In general, those applications with high suction and discharge

pressures on dense gases will absorb the greatest power per

unit displacement. The more energy involved in the compres-

sion, the stronger the gas pulsations will be coming out of

the compressor discharge ports. These pulsations are the

driving force to excite the oil separator and discharge line to

act like a speaker and produce noise, as well as to produce

structure-born vibration.

An application at 350 psi. discharge pressures on a dense

refrigerant can be expected to produce more noise and vibra-

tion than the same compressor at 200 psi. discharge pressure

or compressing a refrigerant of lower density.

In applying screw compressors at high pressures, the cus-

tomer must be prepared for the fact that package vibration

and noise will be higher than the values predicted for normal

refrigeration duty.

Proper foundations and proper installation methods are vital

at high power conditions and even then, the customer must

be prepared for the possibility that sound attenuation or noise

curtains may be required to reduce noise to desired levels.

PMC

Figure 5. Flange Loading - Forces and Moments

Because many applications are somewhat different from

previous experience, it is impossible to accurately predict

overall noise and vibration levels before equipment is started

and running at plant conditions.

The guidelines given in this publication can prevent most

noise and vibration problems with screw compressors, but

for high pressure custom applications, a guaranteed noise

level is impossible to predict prior to installation.

Customer expectations must be tempered with the under-

standing that customized compression systems will vary from

one application to another in achieved noise and vibration

levels. If these issues are addressed before a system is in-

stalled, a more satised end user will be the result.

FLANGE LOADING

External piping loads impose forces and moments in three

geometric planes. See Figure 5. Since circumstances vary

from installation to installation, there is no one set of ange

loading values which Frick can provide for all cases. Our

experience indicates that maintenance of coupling alignment,

especially for compressors and pumps, is the critical limiting

factor. From a practical or service point of view, alignment

is more of a concern than ange strength, pipe stress, joint

stress, casing stress, etc.

Although the ideal loading on any ange or connection is

“zero”, it is not practical to expect “no” affect from external

piping forces and thermal expansion.

The Allowable Flange Loads Table reects a realistic approach

to allowable ange loadings and provides some guideline for

the installation of Frick equipment.

SCREW COMPRESSOR

FOUNDATIONS

070.210-IB (JUN 2018)

Page 7

NOZZLE SIZE -

NPS

(Inch)

MOMENTS (ft-lbf) LOAD (lbf)

AXIAL VERTICAL LATERAL AXIAL VERTICAL LATERAL

MRMCMLPVCVL

1 25 25 25 50 50 50

1.25 25 25 25 50 50 50

1.5 50 40 40 100 75 75

2 100 70 70 150 125 125

3 250 175 175 225 250 250

4 400 200 200 300 400 400

5 425 400 400 400 450 450

6 1000 750 750 650 650 650

8 1500 1000 1000 1500 900 900

10 1500 1200 1200 1500 1200 1200

12 1500 1500 1500 1500 1500 1500

14 2000 1800 1800 1700 2000 2000

ALLOWABLE FLANGE LOADS: ANSI CLASS 150, 300

JOHNSON CONTROLS

100 Cumberland Valley Avenue

Waynesboro, PA 17268-1206 USA

Phone: 717-762-2121 • FAX: 717-762-8624

www.johnsoncontrols.com/frick

Form 070.210-IB (2018-06)

Supersedes: 070.210-IB (2014-04)

Subject to change without notice

Published in USA • 06/18 • PDF

June 2018 Form Revisions

p.3 – Updated anchoring options text (existing concrete ooring)

– Updated Frick Industrial Refrigeration logo throughout

– Updated formatting throughout

Frick Screw Compressor Foundations Installation guide

Brand: Frick

Model: Screw Compressor Foundations

Type: Installation guide

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Frick Screw Compressor Foundations Installation guide

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