PNR 10-Q Quarter ended March 31, 2012

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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-Q

For the Quarterly Period Ended March 31, 2012

OR

Commission file number 000-04689

Pentair, Inc.

(Exact name of Registrant as specified in its charter)

Registrant’s telephone number, including area code: (763) 545-1730

Indicate by check mark whether the Registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the Registrant was required to file such reports) and (2) has been subject to such filing requirements for the past 90 days.  Yes þ No ¨

Indicate by check mark whether the registrant has submitted electronically and posted on its corporate web site, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (§223.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files).  Yes þ No ¨

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a smaller reporting company. See definitions of “large accelerated filer,” “accelerated filer” and “smaller reporting company” in Rule 12b-2 of the Exchange Act. (Check one):

Indicate by check mark whether the Registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act).  Yes ¨ No þ

On March 31, 2012, 99,048,375 shares of Registrant’s common stock were outstanding.

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Pentair, Inc. and Subsidiaries

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See accompanying notes to condensed consolidated financial statements.

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See accompanying notes to condensed consolidated financial statements.

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See accompanying notes to condensed consolidated financial statements.

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Condensed Consolidated Statements of Changes in Shareholders’ Equity (Unaudited)

See accompanying notes to condensed consolidated financial statements

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Notes to condensed consolidated financial statements (unaudited)

We prepared the unaudited condensed consolidated financial statements following the requirements of the Securities and Exchange Commission (“SEC”) for interim reporting. As permitted under those rules, certain footnotes or other financial information that are normally required by accounting principles generally accepted in the United States can be condensed or omitted.

We are responsible for the unaudited financial statements included in this document. The financial statements include all normal recurring adjustments that are considered necessary for the fair presentation of our financial position and operating results. As these are condensed financial statements, one should also read our consolidated financial statements and notes thereto, which are included in our 2011 Annual Report on Form 10-K for the year ended December 31, 2011.

Revenues, expenses, cash flows, assets and liabilities can and do vary during each quarter of the year. Therefore, the results and trends in these interim financial statements may not be indicative of those for a full year.

Our fiscal year ends on December 31. We report our interim quarterly periods on a 13-week basis ending on a Saturday.

In connection with preparing the unaudited condensed consolidated financial statements for the three months ended March 31, 2012, we have evaluated subsequent events for potential recognition and disclosure through the date of this filing.

In May 2011, the Financial Accounting Standards Board (“FASB”) issued authoritative guidance to improve the consistency of fair value measurement and disclosure requirements between US GAAP and International Financial Reporting Standards. The provisions of this guidance change certain of the fair value principles related to the highest and best use premise, the consideration of blockage factors and other premiums and discounts, and the measurement of financial instruments held in a portfolio and instruments classified within shareholders’ equity. Further, the guidance provides additional disclosure requirements surrounding Level 3 fair value measurements, the uses of nonfinancial assets in certain circumstances, and identification of the level in the fair value hierarchy used for assets and liabilities which are not recorded at fair value, but where fair value is disclosed. This guidance is effective for fiscal years and interim periods beginning after December 15, 2011. The adoption of this guidance did not have a material impact on our financial condition or results of operations.

In June 2011, the FASB issued authoritative guidance surrounding the presentation of comprehensive income, with an objective of increasing the prominence of items reported in other comprehensive income (“OCI”). This guidance provides entities with the option to present the total of comprehensive income, the components of net income and the components of OCI in either a single continuous statement of comprehensive income or in two separate but consecutive statements. In addition, entities must present on the face of the financial statement, items reclassified from OCI to net income in the section of the financial statement where the components of net income and OCI are presented, regardless of the option selected to present comprehensive income. This guidance is effective for fiscal years and interim periods beginning after December 15, 2011. The FASB subsequently deferred the effective date of certain provisions of this standard pertaining to the reclassification of items out of accumulated other comprehensive income, pending the issuance of further guidance on that matter. We have adopted this guidance as of January 1, 2012, and have presented total comprehensive income in our Condensed Consolidated Statements of Income and Comprehensive Income.

Total stock-based compensation expense was $5.2 million and $5.7 million for the first quarter of 2012 and 2011, respectively.

During the first quarter of 2012, restricted shares and restricted stock units of our common stock were granted under the 2008 Omnibus Stock Incentive Plan to eligible employees with a vesting period of three to four years after issuance. Restricted share awards and restricted stock units are valued at market value on the date of grant and are typically expensed over the vesting period. Total compensation expense for restricted share awards and restricted stock units during the first quarter of 2012 and 2011 was $2.9 million and $3.3 million, respectively.

During the first quarter of 2012, option awards were granted under the 2008 Omnibus Stock Incentive Plan with an exercise price equal to the market price of our common stock on the date of grant. Option awards are typically expensed over the vesting period. Total compensation expense for stock option awards was $2.3 million and $2.4 million for the first quarter of 2012 and 2011, respectively.

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Notes to condensed consolidated financial statements (unaudited)

We estimated the fair value of each stock option award on the date of grant using a Black-Scholes option pricing model, modified for dividends and using the following assumptions:

The weighted-average fair value of options granted during the first quarter of 2012 and 2011 was $9.65 and $8.04 per share, respectively.

These estimates require us to make assumptions based on historical results, observance of trends in our stock price, changes in option exercise behavior, future expectations and other relevant factors. If other assumptions had been used, stock-based compensation expense, as calculated and recorded under the accounting guidance could have been affected.

We based the expected life assumption on historical experience as well as the terms and vesting periods of the options granted. For purposes of determining expected stock price volatility, we considered a rolling average of historical volatility measured over a period approximately equal to the expected option term. The risk-free interest rate for periods that coincide with the expected life of the options is based on the U.S. Treasury Department yield curve in effect at the time of grant.

Basic and diluted earnings per share were calculated using the following:

During 2011, we announced and initiated certain business restructuring initiatives aimed at reducing our fixed cost structure and realigning our business. These initiatives included the reduction in hourly and salaried headcount of approximately 210 employees, which included 160 in Water & Fluid Solutions and 50 in Technical Products.

Restructuring accrual activity recorded on the Condensed Consolidated Balance Sheets is summarized as follows for the three months ended March 31, 2012, and April 2, 2011, and for the year ended December 31, 2011.

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Notes to condensed consolidated financial statements (unaudited)

6.         Acquisitions

In May 2011, we acquired as part of Water & Fluid Solutions, the CPT division of privately held Norit Holding B.V. for $715.3 million (€502.7 million translated at the May 12, 2011 exchange rate). CPT’s results of operations have been included in our consolidated financial statements since the date of acquisition. CPT is a global leader in membrane solutions and clean process technologies in the high growth water and beverage filtration and separation segments. CPT provides sustainable purification systems and solutions for desalination, water reuse, industrial applications and beverage segments that effectively address the increasing challenges of clean water scarcity, rising energy costs and pollution. CPT’s product offerings include innovative ultrafiltration and nanofiltration membrane technologies, aseptic valves, CO2 recovery and control systems and specialty pumping equipment. Based in the Netherlands, CPT has broad sales diversity with the majority of 2011 and 2010 revenues generated in European Union and Asia-Pacific countries.

The fair value of the business acquired was allocated to the assets acquired and liabilities assumed based on their estimated fair values. The excess of the fair value acquired over the identifiable assets acquired and liabilities assumed is reflected as goodwill. Goodwill recorded as part of the purchase price allocation was $451.8 million, none of which is tax deductible. Identifiable intangible assets acquired as part of the acquisition were $197.2 million, including definite-lived intangibles, such as customer relationships and proprietary technology with a weighted average amortization period of approximately 10 years.

CPT’s net sales and income from continuing operations for the three month period ending March 31, 2012 were $68.2 million and $1.6 million, respectively.

The following pro forma consolidated condensed financial results of operations are presented as if the acquisitions described above had been completed at the beginning of the comparable period:

The 2011 unaudited pro forma net income was adjusted to exclude the impact of approximately $12.9 million in non-recurring items related to acquisition date fair value adjustments to inventory and customer backlog. Acquisition-related transaction costs of approximately $8.0 million associated with the CPT acquisition were excluded from the pro forma net income in the 2011 period presented. The impact of these items were included in pro forma net income as of January 1, 2010.

These pro forma condensed consolidated financial results have been prepared for comparative purposes only and include certain adjustments, such as increased interest expense on acquisition debt. They do not reflect the effect of costs or synergies that would have been expected to result from the integration of the acquisition. The pro forma information does not purport to be indicative of the results of operations that actually would have resulted had the combination occurred at the beginning of each period presented, or of future results of the consolidated entities.

In January 2011 we acquired as part of Water & Fluid Solutions all of the outstanding shares of capital stock of Hidro Filtros do Brasil (“Hidro Filtros”) for cash of $14.9 million and a note payable of $2.1 million. The Hidro Filtros results of operations have been included in our consolidated financial statements since the date of acquisition. Hidro Filtros is a leading manufacturer of water filters and filtering elements for residential and industrial applications operating in Brazil and neighboring countries. Goodwill recorded as part of the purchase price allocation was $10.1 million, none of which is tax deductible. Identified intangible assets acquired as part of the acquisition were $6.3 million including definite-lived intangibles, primarily customer relationships of $5.5 million, with an estimated life of 13 years. The proforma impact of this acquisition was not material.

Additionally, during 2011, we completed other small acquisitions with purchase prices totaling $4.6 million, consisting of $2.9 million in cash and $1.7 million as a note payable, adding to Water & Fluid Solutions. Total goodwill recorded as part of the purchase price allocation was $4.3 million, none of which is tax deductible. The proforma impact of these acquisitions was not material.

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Notes to condensed consolidated financial statements (unaudited)

Inventories were comprised of:

The changes in the carrying amount of goodwill by segment were as follows:

Accumulated goodwill impairment losses were $200.5 million, $200.5 million and $0 as of March 31, 2012, December 31, 2011, and April 2, 2011, respectively.

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Notes to condensed consolidated financial statements (unaudited)

The detail of intangible assets consisted of the following:

Intangible asset amortization expense was approximately $9.8 million and $6.4 million for the three months ended March 31, 2012 and April 2, 2011, respectively.

The estimated future amortization expense for identifiable intangible assets during the remainder of 2012 and the next five years is as follows: